93 Cutlass Supreme engine question

[Brads93]

Good morning, I have a 1993 cutlass supreme with the 3.4L engine. Car has 122,000 miles and has been a very very strong running engine. Previous owner replaced the typical head gasket leak problem and appeared to have replaced the intake gasket(s?) at same time, and the car has about 20,000 miles on it since all that was done.

Over the last few months, after the car sits about a week or two (we don't drive it alot), it starts very sluggishly and I can't keep it running at all unless I floor it for about 2 minutes. As of last week, the car is starting to blow white smoke out the exhaust.

Here is what we have done:
1. replaced the IAC and TPS within the last 2K miles
2. my mechanic tested the MAP sensor and found no issues, and no leaks only 3 weeks ago
3. ran a vacuum (smoke test) check on the engine and found no vacuum leaks (this was also done 3 weeks ago).

4. did a compression test a little over a year ago and found no problems
5. I have run throttle body cleaner thru the air intake (and map sensor port) and EGR port about 1,000 miles ago and it ran fine for a while.
6. I ran sea foam thru the gas tank about 600 miles ago (and ran 3 tanks of gas thru since).
7. fuel filter was replaced less than 10K miles ago.

my concern-why is the car blowing out white smoke and why can't I keep it running. After attempting to start the car yesterday, it would barely run and was very sluggish and would eventually die. I was concerned with the white smoke so i just turned the car off and never even drove it.

A quick and simple dipstick oil check shows nice clean oil (I changed it about 1K miles ago). Did seem to have a little too much oil in it.

I see no paper work from previous owner the timing belt was ever replaced (but the car runs like a dream cruising down the highway...). Fuel pump has never been replaced but my mechanic said it tested fine. Could there be an oil pump, timing belt, other sensor issue? Mechanic said car does not have a PCV valve so nothing along that line has been addressed/replaced but could there be something we are overlooking related to crankcase ventilation and thats producing white smoke exhaust?

Help!

[aleekat]

Does the smoke smell sweet? You need to do another compression test.

[Brads93]

I don't know if I would describe it as sweet but it does not smell like bad engines I have seen before that were going bad (due to lost compression, bad rings, etc). It does not smell like burning oil either.

[aleekat]

Usually black/blue smoke is oil. White, coolant or water. Any chance you got a bad tank of gas? Add a bottle of the anti-water stuff.

[Tech II]

I agree...white smoke is usually coolant. Have you checked your coolant level?

One thing you can try is, get the car to normal operating temp.....let it cool a bit and SAFELY attach a coolant tester.....overnight....next day, disable fuel and ignition and remove all plugs.....have someone crank the vehicle over.....if coolant comes out of the spark plug holes, you found your problem....

Is this the 3.4 DOHC engine?

[Brads93]

Yes, its the 3.4 L DOHC engine Olds had in 1993. We have not checked the coolant yet, other than when I check it cold (take radiator cap off) it appears more than full. I don't rely on the recovery tank. Is there something I should be bracing myself for if its coolant related? Any serious internal issues? Radiator was flushed just 2 years ago and has been driven about 3K miles since. Car drove like a dream about 2 weeks ago when we took it on a long road trip. This sluggish and rough idle has been an intermittent problem off and on all summer long. when the car is warm it runs fine. If it sits over night the symptoms return (can't keep it running, rough idle, now white smoke).

[Tech II]

Yes, if coolant comes out of the spark plug holes, you have a head, head gasket problem.....

[Brads93]

I was talking with a buddy of mine yesterday and we began to question that it might be a bad fuel injector(s). We are going to attempt getting to the injectors and checking them out.

The head gasket was just replaced 11K miles ago. I sure hope that is not the culprit.

[aleekat]

Originally Posted by Brads93

I was talking with a buddy of mine yesterday and we began to question that it might be a bad fuel injector(s). We are going to attempt getting to the injectors and checking them out.
.

Not very likely.

[Brads93]

Well, we worked some more on the car today (since I had the day off). We contemplated it was a bad fuel injector (s) but come to find out, when we started taking the plenum off, there was oil everywhere. it appears someone had taken off the pcv valve and never put one back on...

So, after several hours of studying the chassis service manual supposedly specfic to this car, a few google searches, and even going to several parts stores, we found out the 1993 supreme 3.4 L engine had 2 designs for pcv valves. Apparently mine must be a generation II (late in 1993 production year?) pcv valve design. Long story short, this car apparently is supposed to have a pcv valve but where????? The service manual shows a pcv valve (and even gives an AC Delco part number for it) but the diagram does not match my car at all. The parts stores show a generation I is a single port pcv valve; a generation II valve is a two port deal. my service manual only shows the single port design with a plunger inside it-not the clicker ball design.

I am wonderng if this has been my problem all along (missing pcv valve). We went ahead and put a pcv valve inline between the vac hose feeding the inlet port on the plenum and the hose leading to the valve cover. the service manual made it look like there should have been a pcv valve going in the rear valve cover but after investgation on my car, that port has a pipe inlet that appears sealed in and not designed to be removed nor would it be large enough to accommodate a pcv valve.

so, does anyone have a diagram showng a pcv valve for this car that would be inline on two vacuum hoses (or somewhere else)? I have had a few folks say this car does not have a pcv valve, but, with oil slung everywhere in the plenum and the air filter, I beg to differ.

the car started right up, no rough idle, no white smoke, and ran so far on way home today.

[Brads93]

and today, once again, the car won't stay running on its own when I start it cold until I give it some gas to help it along.

what is my problem??? We have officially checked all (visible) vacuum lines three times now-no leaks, cracks, nor anything unconnected.

Is there a possibility it is ignition control (module?) related?

[maxwedge]

Using a scanner maker sure the coolaant temp sensor reads correctly when cold.

[Brads93]

thanks Maxwedge. I am studying my chassis service manual for the car, trying to study just where the coolant temp switch (and an IAT) sensors are located.

I contemplated those sensors being a culprit, but just did not know where they were or how they played a role.

[jinxyzboi]

Check the auto trans modulator to make sure it's not pulling tranny fluid. If the oil is clean it sure isn't getting water into the oil jornals anywhere.