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Cashmoneyspeed

307 engine problems

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Not sure if this is the right section but i have been reading on here for a few days and i think i may find the answers i'm looking for.

Here goes: I have an '86 Buick Regal with a 307 engine that has 95,000 miles. The Choke/oil light is coming on as soon as the car is warmed up, goes out when accelerating, but comes back on when decelerating and at a stop unless i put it in nuetral. Engine is running real hot and starting to knock a little from under the valve cover( sounds like lifters). Seems like low oil pressure.

I pulled the oil pan to get the the oil pump and the oil pickup screen was clogged with plastic/nylon particles and a couple small pieces of metal, so that may be my low oil pressure issue but i figure i'll replace the oil pump since it's already off anyways. Oil pump gears look good, no scoring or broken anything. I believe the junk in the pickup is from the cam gear. So, i plan on tearing that down to see what the issue is and most likely replacing both the cam and crank gear along with the timing chain.

Also, on the #1 cylinder (driver side front) i can move the piston up and down by hand about 1/4" inch, everything else is tight. What could this be?

Any suggestions on if i should just replace the cam gear if that's what's damaged or replace the entire gear set? Also, i've seen some "performance" gear sets and wondered if that was something i should look into or just a waste of $$$ being that the engine is all stock besides an open air cleaner and the smog pump being removed.

Here's the plastic crap i found in the oil pickup

11030.jpg

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If you can move one piston 1/4" and not move the others I think there's more to worry about then cam gears.

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<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rbl2</div><div class="ubbcode-body">If you can move one piston 1/4" and not move the others I think there's more to worry about then cam gears. </div></div>

I realize that but like what else besides a rod bearing could it be that's worn out, faulty, or broken? And how, if at all, could it be related to the gear getting worn and clogging part of the oil pickup?

It was running like it was brand new until the other day when the oil light came on and it ticked a little bit so i let it cool off, restarted it and it was fine, no noise but the oil light came back on after it warmed up so i tore into it and found the nylon pieces clogging the oil pickup. So, i figure that it's not too hard to do or expensive but i don't want to put it back together without fixing everything that's questionable the first time.

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Guest pfloro

Hello Cashmoneyspeed:

I'm pretty sure that you have the Olds 307 engine which is very durable if reasonably cared for.

If the disintegrating nylon cam gear teeth clogged the oil pump pickup screen, the engine may have been starved for oil. It doesn't take long for major wear (short of a seizure) to occur.

As others have said, the engine is worn and I don't think Band-Aid fixes are the way to go. That #1 piston may have a piston pin and/or rod bearing issue. 1/4" of play is enormous. Other pins, rod or crank bearings may not be far behind.

If you descide on a rebuild, Crane Cams offers a double roller timing chain & gear set. I used this on my '84 Toronado with the same engine (@ 150,000 miles). This setup is stronger and worth the extra $$.

Keep us posted.

Paul

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<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ted sweet</div><div class="ubbcode-body">piston pin area is broken, keep driving and you will have a rod thru the side of the block. </div></div>

It's currently taken apart and not being driven. Only babied it home a few miles on Sunday and then when i started it on Monday, there was no noise or oil light but i figured the pump was bad so started tearing it down anyways.

So far i figure on replacing the gear set, oil pump, and at the very least the #1 rod bearing. Just looking for any info as to how the rod bearing issue could be related to everything else or if i was just lucky i had the oil pan off and was poking around looking for anything out of place. If it makes any difference, there has never been any abnormal noise from the engine, no smoking or loss of oil, and i have meticulously maintained it. Oil/filter is changed every 4-5 months (1000 miles).

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As long as the engine is apart pull #1 piston and have a good look at it. The rod bearing is not the problem. If it is it's because that bearing is no longer there. I suspect the problem is in the wrist pin area. Pulling the rod and piston is not that difficult and could answer a lot of questions.

What I can't figure out is why it didn't make any noise the next morning.

Good luck.

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You won't like this answer, your engine is starved for oil, running hot, and it knocks; it needs a major overhaul. Tear it down, carefully scrutinize cylinder and crank damage/wear, then send them to a good machine shop for resurfacing/boring/grinding.

A good name roller chain set is a 'must.' So are new bearings, based on new crank dimensions. If your block was bored, buy new pistons & rings (based on the new size).

Some of the problems I have heard about this engine relates to low oil pressure, rocker arm pivot issues, and lifters sticking. If your lifters are varnished and not pumping, get a set of those, and clear the pushrod holes.

A major overhaul usually requires a skilled engine builder. You can do it, with help from an experienced mechanic. There is a learning curve, and you need proper tools. I didn't address the heads, but they are as important as the lower end. I usually balance my crank, flex plate, and damper pulley, all together. While your rods and pistons are out, make them all the same weight. Hope this helps. - Dave Dare

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I had a 87 Olds that ran good to 50,000Mi.never using oil to that point.Then it took 3 Quarts too a hundred miles.Went to the olds dealer,they replaced the motor without ????????it.But they never gave me info as to what went wrong and why.Do any of you reding this know what went wrong???? Might help him as to what to look for.

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The plastic pieces could be from the timing gear. They are coated in plastic to keep them quiet when the chain runs over them.

As said, if you can move a piston 1/4 inch without moving anything else the engine is a time bomb.

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<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Oxnard Montalvo</div><div class="ubbcode-body">The plastic pieces could be from the timing gear. They are coated in plastic to keep them quiet when the chain runs over them.

As said, if you can move a piston 1/4 inch without moving anything else the engine is a time bomb. </div></div>

Yeah, the nylon pieces are from the cam gear. 5 of the 8 rod bearings can be moved by hand so needless to say i'm in the market for a 350.

Here's a quick video that shows how much the #1 rod bearing moves by hand (i'm new to posting videos so not sure if this will work).

th_111005.jpg

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Cash

Since this Regal is not a Grand National I assume it doesn't have to be factory correct. My suggestion is that you replace the Olds 307 with either a Buick 3.8 V6 or a Cnevy 350 of 86 or older vintage. This is the same car as the Chevy Monte Carlo, Pontiac Grand Prix and Olds Cutlass all of which could be had with the Chevy 350. Either engine should be a bolt in with factory parts. Chevy 350's are everywhere and complete rebuild kits are reasonably priced. And, they don't have plastic timing gears, they have sprockets and a chain. Chevy trans to engine bolt pattern is slightly different than BOP, but, you should be able to find a 350 with a TH350 or TH400 trans at a reasonable price.

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Is it true that the original Chevy cam timing gear is not coated with something ( nylon or plastic)?

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<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bob Call</div><div class="ubbcode-body">Cash

Since this Regal is not a Grand National I assume it doesn't have to be factory correct. My suggestion is that you replace the Olds 307 with either a Buick 3.8 V6 or a Cnevy 350 of 86 or older vintage. This is the same car as the Chevy Monte Carlo, Pontiac Grand Prix and Olds Cutlass all of which could be had with the Chevy 350. Either engine should be a bolt in with factory parts. Chevy 350's are everywhere and complete rebuild kits are reasonably priced. And, they don't have plastic timing gears, they have sprockets and a chain. Chevy trans to engine bolt pattern is slightly different than BOP, but, you should be able to find a 350 with a TH350 or TH400 trans at a reasonable price. </div></div>

It definately doesn't have to be factory correct for this car. A sbc 350 with the TH350 is what i was wanting to put in it when this engine went, just happened at the wrong time so i'll be shopping around a little bit before i get one unless a deal comes up. I'm pretty familiar with engines, i just haven't torn down or rebuilt an American V8 since auto tech school years ago, so if i run into any problems i know i can get straight forward answers on here. Any idea if the stock trans would bolt up to the 350? I know it won't hold up to the extra power for very long but just in case i have to budget with the holidays coming quickly and all.

Here's the car, daily driven year round the last couple years while i've been building a Caprice.

Southsideshow8-08082.jpg

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If you assembled an engine in tech school you can rebuild a Chevy 350.

The Chevy bellhousing patterns and the BOP (Buick, Olds, Pontiac) bellhousing patterns are different. So you have to have a Chevy trans for the 350 engine. There are at least 3 different tailshaft lengths for TH350 trans. Go the the Chevy forum and ask and someone can tell you what length will fit the 85 Monte Carlo - Grand Prix - Cutlass - Regal.

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Put an Olds 350 in it, it is a true bolt in. Anything else is going to require various engine specific brackets, and possibly some fuel line and electrical re-routing.

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<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dave Wyatt</div><div class="ubbcode-body">Put an Olds 350 in it, it is a true bolt in. Anything else is going to require various engine specific brackets, and possibly some fuel line and electrical re-routing. </div></div>

Idealy i would love to find a 70's oldsmobile 350 (gold color) to put in but at this point, for the right price i'm willing to have to buy the chevy frame and motor mounts along with a little bit of fuel line re-routing.

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Got to the Olds section and ask. 350's are easy to come by. In fact, if you are close to western Indiana, I've got one available right now. We went with a 455 in my son's 85 Cutlass and no longer need the 350.

And a 455 would be another option, with only minor mods needed.

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6 minutes ago, Ramirezantonio1409 said:

I have a 1986 Oldsmobile cutlass supreme .  when i start it it sounds like its starving for oil until i put it in drive.  then it will sound fine for about 30 seconds and it will sound like its starving for oil again.  Just had the engine rebuilt last fall.  Any suggestions

Two suggestions. First, start your own thread instead of resurrecting one that's over a decade old. Second, install a real oil pressure guage and see what's really going on with the oil pressure.

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