Unsolvable overheating?

[Guest]

The Buick 350 in my 70 Wagoneer wants to over heat no matter what I do. This is a list of the things I have done over the last 18 months trying to fix the problem - thermostat (4X),water pump (2x), radiator rodout(2X), radiator cap, headgaskets, radiator hoses, 7 Blade fan, fan clutch, electric pusher fan, backup temp gauge, Edelbrock 1406 carb, ta performance intake, new distributor, compression test (satisfactory results), timing check (satisfactory results). One thing I haven't examined is whether or not I have spun a bearing simply because I don't know how. <BR>In the city and on the freeway I am generally fine for about 10-15 miles depending on grade, then the temp starts climbing up from the 160 mark and just don't stop until I shut it off on the side of the road @240. Wait till the electric fan blows ice cubes out the back of the radiator and I?m off. It will overheat when idling but it takes a couple hours.<BR>When I had the Radiator done I did not have the block flushed as the crusty old guy at the radiator shop exclaimed "dang son that thars some o d cleanest coolant system I ever seen. You don't need to flush that." <BR>The first time I had a problem with it I was flying down the freeway and the Original gauge started to come off of it's normal position then go back. It repeated that cycle for about the next hundred miles but eventually it forget to go back down. Coming back from that trip I had to drive about 75 in the middle of the night because anything less it would be up in the danger zone. <BR>I took the heads off hoping that I had a gasket leak a new set would fix the problem. A couple people had suggested it might have been an intake leak so I sprayed some cleaner fluid around the intake gaskets and found two small leaks at different fittings. Fixed those but no good. Then went after the head gasket. When I had the heads and intake at the shop the guy said the intake was good but thought from the discoloration I might have had a high end leak like maybe a carb gasket. I tried all the easy cheap fixes for that possibility but finally just broke down and got A 4bbl and intake in a hail mary to get it to work - $600 later it still sets there.<P>Brian D. RdHawg<BR>70 Wagoneer w/350 Buick v8 <P>

[brad54]

Premium radiator hoses? It might be that it's collapsing one of the hoses when everything gets warm. But you said you changed them already.<BR>That's my only guess.<BR>Good luck! And let us know what the fix is when you find it!<BR>(Oh yeah--do you have a fan shroud?)

[Guest]

Plugged heater core...I had a plugged radiator on my 66...plugged nearly solid...had it recored...just for kicks I tried to blow thru the htr core...I huffed and I puffed and I barely got any blowback...it too was plugged like the radiator...On the rad. hoses...does the lwr one have one of those springs inside it....these were designed to help prevent hose collapse under excessive pressure....another good thing to try, pull out the thermostat and put it back together, undo the radiator hoses and prop the lower one up as high as possible and fill it up with water...shouldnt take too awful long unless the htr is plugged or something else ...if you get good flow, do you get a bunch of crud out of it??? if so, replace the htr core....and repeat and check the core by itself in the kitchen sink....<P> Good luck...keep us posted on the progress/problem<P> don55

[Guest]

Make sure your timing isn't retarded. <P>

[Guest]

The hoses are good thick heavy ones and do have a spring. I believe I have good flow in the heater core cause it blows hot air like it's satsn's home in there (Especially up around that 240 mark - I rosted my toes last summer trying to keep some heat out) But I will try the blow through thing just to be sure. I don't believe it's clogged though because all the times I've seen the system and the ten times I've drrained the fluid I've never found even hardly a hint of the cruddies. The timing is perfect now thank to my new distributor and advance stuff. Unfortunately I still do not have a fan shroud despite all my attempts to find one or make one.

[Guest John Chapman]

RdH...<P>Well, sounds like you've got a long list of items that it isn't, so here's a couple of ideas:<P>Water Pump: Is it correctly rebuilt? If the impeller and/or impeller clearance is wrong, it won't push enough coolant and may actually stagnate at certain speeds (like a compressor stall.)<P>Blockage inside the engine. Maybe a chunk of old hose lining or something got in there and is wedged in a critical passage. With all you've done so far, I'd invest in a good reverse flush, even if the coolant is sparkling clean.<P>Heater-A/C control valve. You didn't if you have A/C, and I don't know what the control setup is for the Jeep. If there is a vacuum or solinoid actuated valve maybe it has malfuntioned and is blocking the heater return when the heat is not on. If you can figure out how to bypass it and it cures the problem, then you know where to start looking.<P>------------------<BR>John Chapman<BR>BCA 35894<BR>1965 Skylark Convertible (Some Assembly Required)<BR> jmchapman@aol.com

[86 2dr.ltd]

RDHawg,please tell me if you are saying that once you go through this first over heat its not a problem till it sits and then it starts all over again.

[Guest]

Thank you all so very much for sharing your ideas with me cause I'm fresh out of em'! How exactly would a guy go about checking water pump clearances? If I were to pull out the thermostat (to reduce the flow resistance) might that give me a clue as to the pumps performance? Is it possible to just eliminate the mechanical pump and go to an inline electrical one?<BR>If it were that heater a/c control valve wouldn't it fix the overheating problem when I turn on the heater? <BR>Oh yeah, after the Fan cools the engine back down that only gets me the 10 miles back to the house where it's sometimes so hot it stalls when I try to park it :-(<BR> My philosophy on repairing the beast is now "just keep doing the next Idea till it works."<BR><p>[This message has been edited by RdHawg (edited 02-27-2001).]

[Guest John Chapman]

Brian,<P>Impeller clearances have to be checked with the pump disassembled. You can probably check the vane count by looking. Granted, this one is a long shot.<P>If heater full on doesn't ease the problem, then most likely that's working OK... but I wouldn't disallow it.<P>My hunch from you description is that there is a piece of debris lodged in a passage somewhere restricting flow. This would be the one I'd set about correcting first.<P>Good luck!

[86 2dr.ltd]

If you have gotten it this hot you have probably begun to do some damage.Does it pump pressure into the radiator ,thereby pumping coolant backwards out of radiator overflow?If so you have either;<BR>1.warped your heads and blown another gasket<BR>2.cracked head<BR>3.cracked cylinder wall<BR>If the radiator is full and engine is warm does it continously bubble at radiator neck as if air is being pumped into system.<BR>If it is this kind of thing: what happens is one or more cylinders are pumping compression into water jacket.This forms an air bubble at thermostat and thermostat does not work properly then it pumps water out over flow plus because of overheating steams it out as well.<P>I have this problem with my old 330 I6 Ford diesel.One that I tore down to rebuild had so much stuff accumulated in water jacket back by #6 cyl. I began to see why this kept happening.If tons of stop leak was ever once used in this engine plus rust and mineral deposits it may not block flow but it can sure hinder it.<P>Flush your block.Remove thermostat take tiny drill 1/16th smallest in drill index and drill one hole in thermostate large main plate.If air bubble is the problem this will let it go on buy,not a cure but an alternative.I believe you have already done damage to your engine.<P>I hate to ask this but is your thermostat in upside up?Do you have the right radiator.Some one sliped a 3 core in my Olds and I have to keep it moving on the hot days.

[Guest]

I haven't let the engine get hot enough to stall since I did the heads - The oe gauge weren't all that great so you couldn't really tell exactly where you were at. I broke it doing the heads (A good thing?) anyhow since then I've been running a real guage with marks so I make sure it don't go over the 240-250 mark.<BR>as for the bubbling in the radiator - After the thermostat opens you can see the pump pushing fluid through the radiator and I have never seen any bubbling in it or flowing out the overflow. It has been suggested to me to have someone put a smog sniffer over the neck. I've also been keeping an eye on my coolant and have seen no signs of any water in it. <BR>After replacing the thermostat 4x I have developed a pretty consistant habit of always looking at the little picture on the box - look at the part - look at the engine then look back at the picture. So I'm pretty sure it's right. <BR>My father was telling me that many years ago he had an engine that in order to keep it from overheating he had to have the coolant force fed into it to eliminate any possible air pockets. Has anyone else ever heard of this or know someplace that does it?

[Guest]

RDhawg, I had the same problem as u several years ago with my 69 430 Duce&qtr , TRY your Muffler ,I"LL bet it is colapsed inside , or one of your Ex Pipes is pluged , also make sure the heat riser in the exh manifold is not stuck closed, This problem almost drove me to drive the car into a tree , Good LUCK Thom

[86 2dr.ltd]

Out of ideas!Blockage or check that impeller clearence idea.Sorry,I tried.

[Guest COMPACTBC]

Have you had a good radiator shop check your radiator fluid for exhaust gases? If you have an exhaust leak into your cooling system your engine will get as hot as a steam engine! This could be caused by a small crack in the exhaust valve port on a cylinder head. Also a bad catalytic converter will cause a car to overheat bad.<P>------------------<BR><p>[This message has been edited by COMPACTBC (edited 02-28-2001).]

[Guest]

YE-HAW!! I think I made some progress! I replaced the distributor/Vacumn advance and replaced the flow master with a cherry bomb and today it stayed under 210 in town :-). Hotter than I would like, but progress none the less. As for the freeway - well I decided to not see if I could get to 250 but it was well on the way.<BR>The guys @ the muffler shop looked at the flowmaster and said it didn't appear to have any tell-tale signs of damage physical or heat related. (Actually kind of amazing considering all the crud this trucks driven over!)<BR>I seem to have missplaced the manuel to my dwell tach along the way. Would anyone happen to know where the connections go to check dwell? My meter has a + & - and an induction pickup.<BR>OH. The Cat seems to have disappeared somewhere a while ago. And there is no heatriser. Closest thing it had was a tube welded to the exhaust pipe with a foil flex hose to the o.e. air pan. All that went away with the new intake and carb.<BR>Thank you all soooo very much!:-)<BR>

[Guest]

Glad you're making some progress on that. I'm glad my advice I gave over at CarTalk actually went to some good use. Keep us all posted on any more progress you make.<P>------------------<BR>1973 Electra 225-2dr.<BR>93,000 mi. and on its way to 100,000 quick<BR>My poor exhaust tip is crying out for some air shocks <BR>And now,Working Cruise Control!

[Guest]

All I do is Jeeps, V6 300 340 and 350 into CJs. That said, lets talk about Jeeps, all models came with just enough radiator to cool them when stock. A stock Cherokee must have 50/50 anti freeze to stay cool, they will boil on just water. Any thing you do to them ie. bigger tires, different gear ratio, Winch or bumper that restricts air flow, even a roof rack can cause overheating.<BR> some thoughts; I use only AC rated water pumps they have better impellers. any chance the AC condenser is still in the car? if it is, is it packed with mud or bugs?, as a general rule over heat at idle/slow speed is caused by poor air flow across the fins ie. fan, fan cuutch, or poor or missing shroud. over heat on the freeway or grade can be greatly helped with good shrouding but with all the things you checked out my bet is under capasity or a colapsed lower hose. <BR> I use the 350/th400/mld20 combo in CJ7s I pull them out of Wagoneers and PUs. I have found not even the 3 core V8 CJ radiator will keep them cool so my Rad man builds a taller wider unit with a high fin count core and we shroud everthing both in front and behind the radiator. I have yet to see an electric fan alone be enough to cool a V8 Jeep. even the extra pushers and pullers don't work at freeway speed in some cases they even block speed driven air through the grill. Thats another thing, Jeeps have small grill openings. <BR> I would bet against head or gasket problems, the way you discribe your problem is not indicative of compression leak or thermostat problem. The other thing that can bring heat to the rad is the auto trans. A slipping trans builds big heat and a just ok radiator my not be able to get rid of it. <BR> Tell me more about the Wagoneer, what isn't stock, did it and does it now have the full fan shroud, where do you live?JIM

[Guest]

Prettymuch everything is bone stock except the 31 tires but it had those when I first got it and no fan shroud but no overheating. The A/c condensor is still there (Until the first good day I get to remove it.) I am thinking you may really be onto something with the Trans. It has leaked at the front case shaft seal since day 1 but I've always had a pretty good habit of making sure to top off B4 going anywhere. It has good glue-you-to-your-seat get up and go with no noticable slipping so I'm left to wonder?<BR>I live in the S.F. Bay area. and I greatly appreciate your help. (Even if you have been stealing all my parts for all those puny CJ things.)

[brad54]

You know, talking about the A/C condensor reminded me of something: I pulled out a guy's radiator to straighten the fins and detail it for a how-to article, and when I removed it, we found that over half the area was plugged with leaves/debris. The condensor was in front of the radiator, and it looked fine. There was a trim cover going over the top of the two (rad. and cond.), and connected to the core support, so you couldn't see down between the two, and there was a splash apron under them. We have absolutely NO IDEA how that debris got in between the two, because there were no opening for stuff to get there. But it did. After cleaning the radiator, he had to reset his timing and go three "steps" lower for his thermostat! He'd also changed hoses and water pumps trying to keep it running cooler.<BR>I'm sorry I didn't remember this earlier-0occasional sufferer of cranial rectumitis.<BR>-Brad

[Guest]

I am wondering if your heater works, if it does have you ever turned it on full blast on the freeway? I use this as a test to check on capasity it generaly won't stop overheating just slow it down. Have you owned the Wagoneer long enough to know it wasn't overheating before? The only thing worse than stock Jeep cooling systems are stock Jeep gauages. Just smell your trans fluid to tell if its burnt if its pink/red and smells ok you don't have a trans heat problem. Did this problem start after a day of 4X4ing? What fan do you have on it now. And did you check the heat riser when you put on the new exhaust? don't remove the AC compressor you can make a handy air compressor out of filltires or air mattresss or run air tools. Did your rad guy rod your radiator or just boil and flush. silicone seal is the worse for pluging tubes it will not come out with out a good rod job. JIM

[Guest]

Well I'm sad to hear you say that cause in your absence the transfer case and drive shafts - well they're laying on the kitchen floor on my way to the transmission (Figured it needed a seal job anyway!) <BR>The heater works well enough to roast your toes inside yer boots.<BR>I ran the wagon on a couple of trips before I started having these problems so I'm fairly certain it weren't that way B4. I was on the freeway going to my hunting spot when it started and since then have put in a new temp gauge. There is no heat riser to speak of or one of those exhaust valve things. <BR>I am running a 19" 7 blade fan on a new fan clutch off the engine and have a 17" pusher in front. <BR>The A/C pump is in the conversion process as we type. I just need to find time to make up some tanks, oil change in the compressor, and install the whole mess (all those parts are also decorations in my meger apt.)<BR>As for the radiator I specifically requested a rod-out and I am working with the assumption that was done. how would silicone seal get in my radiator (I've learned enough over the years to not put any anti-leak crud in my radiator.)

[Guest]

If you are doing the trans be sure you blow out and flush several times the cooler lines and cooler. left over crud in the cooler system is very hard on the new rebuild. If you do want an external cooler go through it first then back to the radiator cooler then to the trans. you can cool the fluid to much on cold days so the radiator keeps it at opperating temp. I have used many ac condensers as trans coolers, they must be flushed and the fins clean and free flowing. I like Toyota, right size, good mounting,very strong,cheap and plentiful<BR> My guess is that your AC compressor is a York two piston type. I pull the head and plug the small hole into the crankcase fill them with 5w15 synthetic engine oil. you will still need to put Marvle Mystery Oil in the intake side now and then for valve lube. I have two friends who swear by Prolong in the intake twice a year I have not yet tried it. <BR> as for how silcone gets in the radiator. too much around the thermostat,timming chain gasket,intake manifold gasket,on hoses,senders,even freeze plugs. I got a 300 out of a wreck a few years ago, just rebuild with all the papers it took THREE radiator rod jobs over six months to get out the sealer. I finaly pulled the engine poped out the freeze plugs to see what was inside the plugs where still half covered and the water jacket had a hand full in each side. My rad tells me its his #1 pluger not rust or scale, it will not set up fully in antifreeze so it keeps stringing off. Worse yet is to get it a fuel system. Its great stuff if used properly.<BR> double check your fan clutch, when the engine is cold you should be able to easly turn the fan blades with the engine stoped when it 220 and you turn off the engine you should not be able to turn the fan with out some force. Build or buy a shroud. The best wrecking yard for amc/jeep is J&W in Roseville, Ca. not cheap they just have the parts, and very nice people. <BR> Where is your "happy hunting" place? JIM

[Guest]

Thanks for the info on the oil I hadn't as of yet heard that; and for the info on the cooler. I was told that to test the fan clutch I should use a rolled up newspaper with the engine at temp and try to stop the fan - it kind of looked like snow as my paper disintegrated in my hand. I tried to build a shroud with fiberglass once; that was a waste. and JW returned a nada e-mail to me in reference to my request. And I haven't seen even a hint of nor has either of my radiator guys said anything about finding any silicone in there.<BR>One other thing I wanted to ask you about, since I won't be needing my A/C condenser anymore and I already have an external trans cooler. I was considering tying it in after my heater core to use up under the truck with an fan to help my cooling problem should this thing with the trans not work. Except for the obvious limitations of mud and trail hazards do you think it would help or create any other problems?<BR>My hunting place is in Monterey CA, I am in Hayward, but I also have other places around the state I like to go.<p>[This message has been edited by RdHawg (edited 03-04-2001).]

[Guest]

One last suggestion. An oil cooler will help keep it cool. It is only a band-aid fix, but it will help. It will also add a little more capacity.

[Guest]

Today I got a 66 J3000 in the shop with overheating problems on the freeway when he loads his 8' cabover camper. I pulled the radiator and took it to my rad guy its an old 3 core he gave me four options 3 core, 4 core, 4 core high fin count and a new 5 core ultra high cooling. the owner went for the 4 core high fin count. I put it in this afternoon and hooked up my 3 axle car trailer (the camper was on) and hit the freeway 65 for 10 miles never got off therm ostat. He is going to Oregon this weekend I will let you know how it works. JIM

[Guest]

Did you get the trans done? My guy came in this afternoon said the truck has never run that cool. He is sold now he wants to know how much to hook the AC back up. JIM

[Guest]

not yet. Too little time/money so I'm taking it slow and steady. I've also kind of got hung on rebuilding the drive shafts. 5 u-joints - no 2 alike :-( Even the local driveline shop can't get it right. I'm supposed to have a guy help me rebuild the Xfer case this weekend. Once all that is done and sitting here to go back in I'm gonna go out and finish pulling the tranny and drop it off at the local shop (Hopefully a couple paydays from now!) <BR>If that don't fix the overheating I am torn whether to do like your saying and go with a high fin count or with the alum racing radiator. Where would I get a high fin count radiator?

[Guest]

I would pull the pan off the trans smell the fluid and check for excess svavings in the bottom of the pan and back of the filter. seeing none and no burnt oil I would put my money in in the cooling system. My rad guy is in Sacramento, I am sure I could find out from him who is worth a darn in the bay and can get you a good core. JIM

[Guest]

I hate to quit now. I feel like I'm half way there. The th-400 has been a perpetual leak since I got it - like a quart everytime I drive it. the landlord don't preciate it in his drive either. About how much $ for the Radiator? I'd really appreciate a line on something up this way, if you think to ask next time you see him. Thanks :-)

[Guest]

I HAD A SIMILAR OVERHEAT PROBLEM WITH MY '71 455 CONV. I HAD A BIG HOLE IN THE BOTTOM OF MY SHROUD AND IT DID NOT FLOW ENOUGH AIR AT SLOW SPEEDS TO COOL WELL. AS SOON AS I REPLACED THE SHROUD, THE PROBLEM WENT AWAY.<BR>IF YOU HAVE NO SHROUD, IT CAN'T BE PULLING MUCH AIR THROUGH. TRY HOLDING A RAG IN FRONT OF RADIATOR AT IDLE. IF IT IS NOT SUCKED UP AGAINST IT THEN IT IS NOT PULLING ENOUGH AIR THROUGH. GOOD LUCK.

[Guest]

I HAD A SIMILAR PROBLEM WITH MY '71 455 CONV.<BR>I HAD A BIG HOLE IN THE BOTTOM OF MY SHROUD AND IT WAS NOT PULLING ENOUGH AIR THROUGH TO COOL AT LOW SPEEDS. I REPLACED THE SHROUD AND THE PROBLEM WENT AWAY. IF YOU HAVE NO SHROUD AT ALL, IT CAN'T BE PULLING MUCH AIR THROUGH. TRY HOLDING A RAG IN FRONT OF RADIATOR. IF IT ISN'T SUCKED AGAINST IT, YOU PROBABLY ARE NOT GETTING ENOUGH AIR EITHER.<BR>GOOD LUCK.

[Guest]

Just got the word from the trans shop. Said the clutches are "down metal to metal, needs a rebuild." I don't know if hes pullin my leg. I hope not. Anyway, maybe well find out by next weekend if that fixes it.

[Guest]

In California you can get back all your old parts. BUT you must ask up front, so call him and ask him to "put your old stuff in a box" you could learn something and keep him a little more honest. Once again take this time to blow out and rince your cooler and lines. If your guy can find a deeper pan, some one tons and motohomes or aftermarket it could help, a good cooler is better both are best. JIM

[Guest]

Well the deed is done! I have reinstalled everything, removed the a/c condenser, replaced the miniscule trans cooler with the largest one available. I placed the cooler as far away from the front of the radiator as I could while still getting some air flow over it. rebuilt both drive shafts (for kicks) and rebuilt the transfer case. <BR>The results:<BR>I don't lay a smoke screen down the freeway anymore (curtosy the leaking x-case seal). And my truck made it over the dublin grade for the first time in 18 months!<BR>Thank you all SOOOOO very much! :-)<P>It is still running really warm though. @ idle I got 230 before I shut it off and I was running 220 all the way over the grade but holding. So if you got a lead on that 4 core here in the bay I think I could still use it.

[Guest]

good deal!!!! go to my post of 3-2-01 you now have a hot at idle, warm freeway problem, it's time to build a shroud. If it doesn't work it will still fit a 4 core. I take the measuments of the rad then the fan offset mesurements draw it out on paper and head to the bone yard. I have ended up cutting top to bottom, side to side, and using two to make one. I use foam tape against the radiator and the push through cooler mounts to hold it in place. If you do have a seam I use pop rivets or wire ties to hold them together. I have done several lately split left and right and don't wire tie them together until both halves are mounted. This can make installing easy with out removing the fan. also look in front of the rad for any path air can go once it's through the grill other than through the rad. block or divert air so the only way out is through the rad. If that doesn't bring down your temp I would be suprised. let me know JIM

[Guest]

RDHAWG, A SHROUD IS EXCEEDINGLY IMPORTANT I HAD A 455 IN A 69 SKYLARK, WITHOUT A SHROUD IT OVERHEATED ALL THE TIME. MY SOLUTION: 7 BLADE FLEX FAN FROM HAYDEN,HOME MADE SHROUD OUT OF A 79 OLDS 88, FOUR ROW RADIATOR AND A 180 STAT, PEOPLE ALWAYS TRY GOING WITH A 160 STAT THE PROBLEM WITH THIS IS, IT GETS TO 160 AND STAYS OPEN-IT NEVER CLOSES, THEREFORE IT DOES NOT KEEP THE COOLANT IN THE RADIATOR LONG ENOUGH TO COOL IT DOWN. ALSO NO FAN CLUTCH THEY STEAL HORSEPOWER.

[Guest]

I´s the water boiling,if not check temp sending unit,You do have to get the fan shrud in place or make one on your own.

[Guest]

Just wanted to dig this ancient post back out to say I think I have finally fixed it!<BR>Two words "Howe Radiator" Bought that beuty from summit for 200$ installed it and a fan cluch eliminator and now it barely goes over the thermostat temp! yee-Haw! Thanks for the help everyone especially Jimmie - ya'll R welcome to come wheelin' any time!

[Guest]

Hi all , i don't really have any advice as i am reading your posts for personnal knowledge ( classics are new to me) . But i had a question , my 1970 skylark has a 3 core rad and it used to have a smaller one which looked like a transmission rad , but nothing was connected to it so i removed it!<BR>I wanted to know if my rad was enough for the big 350 that's in the skylark AND the transmission ???<BR>

[Guest]

Rule of thumb on radiator size is 1sq inch of core per CI of displacement plus 50. I.E. a 350 req 400 SQ. inches of Rad. core or 20" by 20" if you was takin bets I'd guess the skylark used to have AC and that's what the cooler you removed was for. look and see if your big radiator doesn't have a couple 3/8 steel flex lines going into one of the tanks - that would be your trans cooler (requires more core area to remove the extra heat.)