I take back everything bad I said about cold-start issues. My '89 'Cruiser's 307 has been a bit wonky for some time now with some "scary bottom-end noises" and thocka-thocka sounds, but either because it is hot now or purely-coincidentally the stakes have been raised.

A little while ago I would get "chugging" when I came to a stop (like at the end of an onramp) if I had been driving for a while, but other than the winking OIL/CHOKE lamp and some hesitance at idle and flat-footed acceleration from that stop, everything was fine--or as fine as could be expected--and the problem went away after what I think is just cooling down.

Now after 20 mins. of driving the light comes on full at a stop and stays on, chime and all. Once she's rolling the least little bit--or I put her in neutral--the light instantly goes out. The stumbling "off the line" is worse, too, but it's still more annoying than anything.

All fluids are up to spec (most new, actually), but after 170k miles without being apart at all (including carb) I fear that the engine-going-for-good threat-level has moved from "elevated" to something MUCH closer to "imminent".

Then again, you probably know the twenty-cent part I need that will instantly rebuild the engine so I don't need to worry about this at all, right? RIGHT?!?

 

Chugging when coming to a stop is a clear symptom that your lockup converter solenoid is sticking. Usually noticeable after engine warms up. The converter lockup feature is not releasing and it is almost like coming to a stop in a stick car and not pushing in the clutch. I dont know if the part is still available and you need to drop the trans pan to change and other than that its an easy fix. I am pretty sure the 89 used this feature....I know the 85's did and had 2 Oldses with this problem. As for the oil light that could be something else....

 

I'm thinking so.

After you change the lockup converter solenoid as Joe suggested (you'll need your transmission to work well, even with the new engine), you can replace the $4.00 oil pressure sender at the front, top of the engine (sorry, it's not 20¢), and if the Oil light still comes on at low RPMs hot, then you need to start trying to locate your next engine.

A rod knock and low oil pressure is not an auspicious combination.

- Eric

 

I agree with this diagnosis 100%. I had the same symptom with my 87 442, replaced my TCS, and it completely fixed the problem. It was really quite an easy replacement and I got the bonus of being able to replace my trans fluid, which I had been wanting to do anyway.

 

My old 85 Delta did that right before the 307 when BOOM when I spun a bearing. I have a video of it on you tube. Car still ran under it's own power, just didn't go very far.

I changed the oil sending unit as well but it still did it. Are you sure there is enough oil in the motor. That was my issue. The *** that changed my oil only put in 2 quarts. By the time I figured it out, I changed the oil and saw only 2 quarts come out, and put in 5 quarts, 2 days later, engine was done

Kept getting BS excuses of why thr oil light was comming on, so I didn't do anything. That mech didn't like working on my car, so he decieded to kill it

 

I concur. Oil light is coming on because the engine is almost stalling when the TC clutch doesn't release. The solenoid is available through RockAuto.com. ACDELCO 8634960 $49.79

 

So you feel the light is more related to unusually low revs than to unusually low pressure? Interesting. I'll tuck that away in the back of my brain - it could come in handy later.

If it tends to occur that way, then I'd say get an oil pressure gauge, so that you can see what's going on - if the pressure is fine, but then drops when the engine is pulled down by the lockup, that's a good sign, but if it's always a bit iffy, and drops a lot at idle, even out of gear, that's a bad sign.

- Eric

 

I don't necessarily agree with this. My oil light did not come on when I had this problem (I may have been unclear about that in my first post). I think your oil light problem may be unrelated to your TCS, but I would replace the TCS first and then see if the oil light continues to come on.

 

I'm sure that there's probably more than one potential problem going on at once, but I wanted to add to the description to see if it helps.

When I bought her--10 months ago tomorrow!--she was leaking oil pretty bad, which was one of the reasons he was selling her as he thought/was told it was a leak in the pan that would cost a ton to fix. Turns out it was a crack in the sending unit, so I had that replaced within days of getting her home.

As there was a little "lower-end noise" as well, I started replacing her oil probably too often for it to matter, but I've not only been checking it for shavings or whatever but also to make sure that "good" oil (in the right amounts) was in there just in case [it goes in gold and comes out gray/black, so I can only guess at the crud that's built up in there].

As for the transmission, there could very well be an issue that I'm just not seeing while focused on the engine. As I don't know exactly how she's supposed to work I couldn't say if there was an issue, but to me she shifts fine. It will, however, be the next thing on my agenda.

[After I find out why, with proper amounts of oil and a new(ish) sending unit that the light's coming on (especially ONLY when fully warmed-up). Oh, and why it's only at a full stop while in gear. And...]

 

Oil's viscosity (thickness) changes with temperature.

It becomes thinner as it gets hotter.

Thinner oil has an easier time squeezing through small places (like journal bearings), and so any pressure placed on it by the oil pump (which, itself, is likely worn) will "bleed down" faster when the oil is hot than when it is cold, resulting in lower oil pressures when hot.

As mentioned, as the engine wears, metal is worn from bearing surfaces, increasing bearing clearances, which, when extreme, will reduce oil pressure, especially when hot.

Finally, the oil pump is driven by the engine, at a speed proportional to the engine speed.
More speed = More pressure.
Less speed = Less pressure.

So, increased bearing clearances from wear + hot, thin oil + low RPMs = drop in oil pressure.

Get a gauge, check your actual pressure, and go from there.

If your pressure is dropping because of unusually low RPMs because of sticking transmission lockup, you've probably still got a low pressure to begin with, just not quite low enough to trigger the pressure light.

- Eric

 

I'm going to be the naysayer here, and tell you the motor is junk. Don't drive it anymore, and don't bother saving the metric trans with 170k on it.
That oil light doesn't even bother to come on unless you have less than 7 psi or so.
At 7psi I'll bet it would last about 5 miles on the interstate before puking out a rod cap and 5 quarts of oil all over the road.

Maybe it could have a longer time to live if you just took it to the corner store every now and then.
BUT if you want to drive it, put something fresh and decent in it.

That is a cool wagon, it deserves better than this sad tale I am reading right now.

 

I have to agree with Jay.

Look for a running 350 or 455 and just drop it in. That's what I would do.

I would also make a table out of the old 307.

 

That's a cool table, but it'd be a bitch to move...if you ever sell the house, sell it with the house!

 

I just "sucker changed" her oil (drained it and put it back in) and it has the proper amount based on the volume I changed and the dipstick.


You have no idea. I hate to be forced into these corners, but I'm quite strapped for cash. I've put feelers out regarding a replacement engine (350, etc.) but can't find a suitable match.

[IF ANYONE KNOWS OF A SUITABLE "DROP IN" ENGINE/TRANS (if necessary) AND SOMEONE TO DO THE SWAP, LET ME KNOW...]


As for the oil, I'm using the Castrol High Mileage oil in 5W30 form (as it says on the filler cap). I don't think I can get any "better" results by going to another weight, but if I can, let me know...

[And thanks for the help. I'm not too proud (despite being an automotive journalist) to ask for "professional" advice and appreciate that you are taking the time to help me with this. Next, onto the brakes...]

 

You're using 5w30 in a beast like that?

Just drop in some 20w50, and watch that light flick off!

- Eric

 

Casters can be your best friend. I am strong considering doing this with the Alero's block when I rebuild the block that's in my basement

Yeah 5w30 is not good in a 307, too thin, I use 10w30 in mine