Guest Copper81 Posted December 1, 2009 Share Posted December 1, 2009 I have been trying to solve this issue for a LONG time with no real success and have looked at many threads and done searches. Now that the much cooler temps are here in Jersey, I am turning to the "Wealth of Knowledge" here for some ideas. In one sentence, it runs very warm (aka hot) in the summer and COLD in the winter. This is for my 88 with 122,000 miles and I have changed out the thermostat with a Stant 180 degree version in order to limit the typical high heat of the coolant system during the summer months. After changing the thermostat, the system seemed to regulate much quicker and was a bit more stable than with the old thermostat. But now with the cooler temps approaching, the car struggles to reach 160 degrees even after 20-25 minutes of daily driving along city streets. I am out of ideas why this doesn't reach at least 180 degrees when it easily reached those temps (and above) when it was just slightly warmer outside (60 degrees or so). It would seem natural to say that the thermostat needs to be changed again but after changing it out last year and not seeing any improvement in heating up in the winter, I am wondering what else could cause this type of problem. By the way, the heater does put out some reasonable heat but it does seem to follow the temp gauge so I do not think a sensor is the issue. Any thoughts/suggestions? Link to comment Share on other sites More sharing options...
Guest NEMO Posted December 1, 2009 Share Posted December 1, 2009 Replace the thermostat. sounds like you got a bad unit. Link to comment Share on other sites More sharing options...
Guest ekvh Posted December 1, 2009 Share Posted December 1, 2009 You have to have the top o-ring shaped piece to ensure quick warm ups. Without it, the sensor floats in the housing and allows water around the stat even though it's closed. Link to comment Share on other sites More sharing options...
padgett Posted December 1, 2009 Share Posted December 1, 2009 There is a second gasket that goes on top of the thermostat and under the water neck. There was a TSB in 1989, 89-6-3, that talks about it and caused engines to just not warm up (3800 is really a cool running engine unless something is rong). I believe it is a FelPro 00427. Link to comment Share on other sites More sharing options...
Guest Copper81 Posted December 1, 2009 Share Posted December 1, 2009 When I replaced the thermostat, I know that I did not use a second gasket on top of the thermostat because I was not aware that one was required. I will go to my parts place and get the FelPro 00427. I'll post some results after I make this change. Thanks for the help! Link to comment Share on other sites More sharing options...
Barney Eaton Posted December 1, 2009 Share Posted December 1, 2009 You could also have a fan issue. The fans at the radiator should not come on until the engine gets up to temp. You might want to check them. Link to comment Share on other sites More sharing options...
BrentS Posted December 1, 2009 Share Posted December 1, 2009 Good luck finding the top gasket. I couldn't find it. And GM wants you to order a Qty of 10 (25535939?).Anyway, sounds like you're having the exact problem I was just having. I made my own "top gasket", and now my car is pegged at 192F. Love it. I went back to the original 195, too. Cool temps sound inviting, but I also like running engines at the temp they were designed for. I had high-idle issues when my car was at 160F-ish, too, when the T-stat was "floating around". I've also learned about "flame front extinguishing" and incomplete combustion, etc. etc, back in the old Engines course I took in college. Plus, there's lots of warnings in the marine industry about running too cool, when people think they can remove their T-stats..........so, 195 seems to be working Ok for me. Link to comment Share on other sites More sharing options...
Guest ekvh Posted December 1, 2009 Share Posted December 1, 2009 I run the 195 in the cold months here, ( Minnesota cold ). I put a 180 in the summer thinking it would help my transmission stay cooler, but except on the open road, it runs 195-215. The fans don't kick in until 210, so the 180 only helped initially. I also read an older post and noticed that the LeBra I have on the front limits air movement a great deal. I have the LeBra to cover a small broken piece from a deer. Removing it means body work. Before next summer I hope to find some piece to open the bottom part of the LeBra and let more air in. Then, I think it will run a bit cooler, otherwise I think I will have the PROMS adjusted to kick in at 195 or so. I don't mind the 195 for the motor's performance. There sure seem to be plenty of them around still with mega-miles on them. I do think the heat could increase the breakdown of the Transmission fluid. When I found out about the missing gasket on the Tstat, I watched mine warm up and it is unbelievably faster with the gasket/donut/whatever it is. Link to comment Share on other sites More sharing options...
BrentS Posted December 1, 2009 Share Posted December 1, 2009 Yeah, I'm still soooo surprised that engineers would ever come up with a one-bolt T-stat flange/elbow................of any kind. Being that there's an o-ring that's installed in a groove on the elbow, it may not leak......but it sure doesn't tighten down properly with only one bolt. Oh well, I consider it a lesson learned for myself.I've also come across performance information regarding engine temp...........in internal combustion engines.....the cooler you run the coolant system, the more heat flow you have into the combustion chamber, with resulting loss of power. I'm sure it's a small amount; just as small as the extra life you may gain out of your tranny by running it at 180 in lieu of 195. Just thinking while I type...... Link to comment Share on other sites More sharing options...
Guest F14CRAZY Posted December 1, 2009 Share Posted December 1, 2009 stuff some cardboard in front of the radiator Link to comment Share on other sites More sharing options...
padgett Posted December 2, 2009 Share Posted December 2, 2009 Shades of Will Rogers.a) The 3800 is designed to be "all in" at anything over 150F. I run 180F which provides pleanty of heat even at 0F. In most materials, decreasing the transients (temperature) by 10% doubles expected life. 180F is an 8% drop. tightening the bolt has nothing to do with sealing, it just holds the waterneck in place. The O-ring does not require tightening to seal. One bolt is plenty. Whether it leaks is a matter of how smooth/clean the bore is.c) The further down a PV curve you start, the denser the charge. The cooler you run the engine, the less likely you are to get detonation on trash gas (87 PON at sea level, less at altitude). The only way the ECM knows how to control detonation is to retard the spark which kills MPG. See OldPA3. Link to comment Share on other sites More sharing options...
BrentS Posted December 2, 2009 Share Posted December 2, 2009 I agree with you padgett on just about everything...........except, my high idle issue problem stopped as soon as I got the normal operating temps back out of the 160's. So, I'm not so convinced on the "anything over 150F", however, I guess it's moot for either a 180 or 195 T-stat.Correct, tightening the hideous one-bolt design does not appear to affect leaking, but I strongly believe it affects leaking past the T-stat, resulting in the ever-plaguing cold temp issue. I very very closely watched the opposite end of the T-stat flange creep up, as I tightened the one bolt; it was not evenly clamping down on the entire T-stat flange. But, thanks to this awesome forum, most should know about this potential problem. Link to comment Share on other sites More sharing options...
charlie1 Posted December 2, 2009 Share Posted December 2, 2009 I do not want to Hijack this post But their appears to be more condensation (NOT COOLANT) in my motor oil since I changed to a 180 Thermostat according to Blackstone Labs who has done 2 oil analysis on my motor oil.Will start a NEW POST once I get more data. Plan on talking to Blackstone labs when I get time.Charlie Link to comment Share on other sites More sharing options...
BrentS Posted December 2, 2009 Share Posted December 2, 2009 Interesting...........Yes, I'm sure the list is very long, for the discussion on the operating temperature (or changing temperature) for internal combustion engines.Condensation in the oil, was not one that I've heard yet. I'd be interested to read that post. Link to comment Share on other sites More sharing options...
padgett Posted December 2, 2009 Share Posted December 2, 2009 Good info but condensate also depends on OAT, garage temp, humidity, and how far you drive.Also checked and the stock idle RPM is slightly higher below 154F (176F in P/N). Never noticed because I kicked my idle up to 700 min (625 stock) for better a/c operation at stoplights. The "cool compensation" is also all in above 154F - this is for the 1988 ANCX PROM. Link to comment Share on other sites More sharing options...
Guest ekvh Posted December 2, 2009 Share Posted December 2, 2009 Before putting my "spacer gasket" in, I thought it wasn't necessary, but soon noticed it took forever to warm up, and when it got real, cold, it wouldn't warm up. With the motor off, and a cool engine, and no pressure to the cooling system, you can squeeze the top radiator hose and hear the thermostat moving up and down from its resting place and the housing. You can even feel a soft click through the hose or the elbow if you put your hand on the elbow. If it's moving, it's got to be letting water around it. One of my old ones shows the pattern left from flowing around on one side of the thermostat. I am convinced it needs it. It should be easy to fashion a piece out of some rubber if you cannot get it. All of the places I have gone have it or can get it and it's cheap. Link to comment Share on other sites More sharing options...
Guest Copper81 Posted December 9, 2009 Share Posted December 9, 2009 Just to follow up a bit on what I started with the heating issue ...I searched NAPA online and saw 3 thermostat gaskets/seals mentioned and ordered all 3 (special orders!). The part numbers are: THM 1081 (fits around the thermostat), FPG 35126 and FPG 35608. I am not sure which of the last two will be necessary but I plan to see what works best to ensure that when this is all put back together that there will be no flowby and thereby causing some bypass of the thermostat. Now all I need is some time and decent weather to install these gaskets. I'll post another update when that finally happens. Link to comment Share on other sites More sharing options...
Ronnie Posted December 9, 2009 Share Posted December 9, 2009 Please add the model of your Reatta, (and any other relative information), to your signature line. It will make it easier for us to help you with answering your questions without repeatedly asking you about the Reatta you own.Click "User CP" in the menu at the top of this page and scroll down to "Edit Signature"Thanks! Link to comment Share on other sites More sharing options...
BrentS Posted December 10, 2009 Share Posted December 10, 2009 If possible, if you find a replacement/aftermarket gasket that fits into the elbow/neck, I would love to see some pictures of it. Because, other posts mentioned aftermarket gaskets that were the style that fit onto the T-stat's flange, which did not seem to fit correctly in my '89.I have yet to see a picture of an aftermarket elbow/neck gasket picture. Link to comment Share on other sites More sharing options...
Guest ekvh Posted December 10, 2009 Share Posted December 10, 2009 Do a search with Padgett's name or Ronnie's name. i think they each had pictures of the gaskets. Link to comment Share on other sites More sharing options...
Guest ekvh Posted December 10, 2009 Share Posted December 10, 2009 Try this: http://forums.aaca.org/attachments/f116/16439d1197164230-thermostat-gasket-19790.jpg Link to comment Share on other sites More sharing options...
Guest ekvh Posted December 10, 2009 Share Posted December 10, 2009 That was from John w/2 Reattas post Link to comment Share on other sites More sharing options...
Ronnie Posted December 10, 2009 Share Posted December 10, 2009 If possible, if you find a replacement/aftermarket gasket that fits into the elbow/neck, I would love to see some pictures of it. Because, other posts mentioned aftermarket gaskets that were the style that fit onto the T-stat's flange, which did not seem to fit correctly in my '89.I have yet to see a picture of an aftermarket elbow/neck gasket picture.My '88 model has the style gasket that goes around the flange. Link to comment Share on other sites More sharing options...
BrentS Posted December 10, 2009 Share Posted December 10, 2009 Yes, I've seen those posts. But my gasket didn't look like the 12337901. It looked like the below (only black). It went up into the neck/elbow to some degree. Link to comment Share on other sites More sharing options...
padgett Posted December 12, 2009 Share Posted December 12, 2009 Actually there are three (but I do not have a part number and not certain where it came from, possibly the '90.) Link to comment Share on other sites More sharing options...
Ronnie Posted December 12, 2009 Share Posted December 12, 2009 Actually there are three (but I do not have a part number and not certain where it came from, possibly the '90.)The photo shows the type of rubber seal that is used on the thermostat in my '88 model. I don't know if it was the type that was used in all '88 models or not. Link to comment Share on other sites More sharing options...
Guest ekvh Posted December 12, 2009 Share Posted December 12, 2009 If I tried to put mine on like the one in Padget's photo above, it would not fit. It would tear apart trying to make it fit. It looks as though there are a few possibilities, but in any case, your car will run better if you have the thermostat pinched securely in place so water isn't sneaking around it. With a cold motor and no pressure in the system, you can here it rattle as you squeeze the upper hose. If it's moving around, it is letting water past it and your car will take longer to warm up. If -20 or more, it took forever to get above 150. Link to comment Share on other sites More sharing options...
Guest Copper81 Posted March 1, 2010 Share Posted March 1, 2010 There is a second gasket that goes on top of the thermostat and under the water neck. There was a TSB in 1989, 89-6-3, that talks about it and caused engines to just not warm up (3800 is really a cool running engine unless something is rong). I believe it is a FelPro 00427.After an incredibly long delay, I have FINALLY taken the time to install the second gasket that fits above the thermostat. I wanted to add that I used a slightly different gasket than what Padgett mentioned above. NAPA showed a Fel-Pro 35126 that fits around the thermostat. I have attached a picture of it (not a great one .. sorry). But after installing this and adding back some antifreeze that was lost in the process, I am very glad to say that my 88 now warms up as it should. Thanks for all the input on this situation. Link to comment Share on other sites More sharing options...
charlie1 Posted March 1, 2010 Share Posted March 1, 2010 In very cold weather I have found it necessary to change back to the 195. Will made a decision next summer if I will change back to the 180. Link to comment Share on other sites More sharing options...
sfair Posted March 1, 2010 Share Posted March 1, 2010 In very cold weather I have found it necessary to change back to the 195. Will made a decision next summer if I will change back to the 180.Goofing with thermostats ended when the last flat head engine rolled off the assembly line. Leave your 195 in year round. There are zillions of cars running around all over the world with the factory thermostat and having no problems. If it does not work, then there is a problem elsewhere.Your thermostat housing bolts will love you for it! Link to comment Share on other sites More sharing options...
padgett Posted March 1, 2010 Share Posted March 1, 2010 Factory warrenty was 5/50. I like to keep vehicles longer than that. Link to comment Share on other sites More sharing options...
BrentS Posted March 2, 2010 Share Posted March 2, 2010 I'm sticking with the factory 195F, too, for now on. My cold-running issue (related to the T-stat gasket) resulted in a high-idle condition.........I'm 95% sure of it. So, temp definitely affects many things (i.e. ECM)........and I don't want to mess with any of that stuff anymore.Additionally, I'm a big proponent of running electrical and mechanical devices at as constant a temperature as possible (and I don't want to re-program fan settings, etc.). Temp fluctuations have many adverse affects............various metals expanding/contracting at different rates, etc...My theory is the car will be just fine with the stock 195F. Link to comment Share on other sites More sharing options...
Guest Telco Posted March 2, 2010 Share Posted March 2, 2010 That's the exact same gasket I've been using for the last couple of months, so far so good. The car warms up within about 3-4 miles now instead of never like before. Link to comment Share on other sites More sharing options...
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