PCV?...Head gasket?...:confused:

81Baby · 12-06-2002, 09:19:00 AM

Ok, I think I have several problems on my son's '81 with a stock 229 boat anchor.

Some background info:
He tells me that after it warms up, it dies when he lets off the accelerator, and it does not want to start when hot.

The evidence:
I suspected the choke and possibly the HEI module. I took off the air cleaner cover to check the choke, and there is oil in the housing. There is also a black spot on the air filter where the breather hose comes in. I started the car, and whitish smoke starts coming out of the breather hose! There is also whitish smoke coming out of the exhaust, and it seems to get worse as the car heats up. The choke works fine though.

We replaced the PCV valve, and there is no more smoke coming out of the breather, but there is still smoke coming out of the exhaust. I also noticed a lot of oil blown on the spark plug wires on the passenger side, and the starter is covered in oil too. This seems like too much oil to be a PCV problem. I pulled a spark plug from the passenger side, and it was definately oily. Then I realized that the valve cover area is not that oily, and the exhaust manifold is not oily either. I would expect a PCV problem to cause valve cover oil leaks.

My Diagnosis:
At this point I am guessing that he has a blown head gasket, and that is why the oil is being blown out so far from the block, and is not higher up on the engine. The smoke could also be steam, but I have had cracked heads before cause steam, and it was always a lot more "smoke" than this.

Questions:
1. Does my diagnosis sound likely?
2. Could a PCV problem cause the engine to burn oil, blow a lot of oil, or even blow the head gasket?
3. Any other ideas?

FYI, we will be replacing this engine with a 350 in the next few months, but we need to keep it running until then.

Thanks

purple81 · 12-06-2002, 02:38:00 PM

As far as the smoking, you're going to need to do a compression check on all the cylinders. If you have a blown head gasket, that may also be causing your running problems, otherwise, forget the HEI module, it has nothing to do with this. I would not rule out the coil, however, but the only way i know how to check those is by replacing them. Your carb may need a good cleaning and rebuild.

tom3 · 12-06-2002, 06:58:00 PM

Can't imagine a headgasket causing this, no oil gets to this on the lower edge, coolant maybe. Thinking maybe the fuel pump is leaking and blowing back? Or maybe the intake manifold is leaking in the rear corner and running down. Some oil in the intake and smoke from the vent hose is normal in the older engine. Smoking exhaust might be a bad sign though. Probably need to clean the area real good with Gunk and try to pinpoint that leak. This car have a computer? Might have a sensor out of spec causing it to run way too rich.

81Baby · 12-07-2002, 09:36:00 PM

Well, I am not sure what is going on now. The car has quit smoking and has not died while idling since changing the PCV valve. The car does have a computer, and I checked the wiring of the sensors and the carb mixture solenoid. Maybe something was loose or dirty...

As soon as I get a chance we are going to clean up the oil from the leak and see if it is gone too.

I am going to keep my fingers crossed and hope that it can hang on until we can get that 350 ready...

76L88 · 12-08-2002, 04:01:00 AM

I would guess the oil is unrelated to the stalling problem. The oil sounds like excessive blow-by from worn or a broken piston oil control ring. Does it smoke more on acceleration of decelleration when vacuum is high?
The dying could be from oil fouled plugs, bad/dirty carburetor, ignition failing when heat soaked. Maybe some of that oil vapor has gotten into the carb and messed it up.

------------------
76 Coupe, now engineless.
86 Z28

"If it aint rusty, it will be"

Eric · 12-08-2002, 06:48:00 AM

You probably had a plugged PCV valve and therefore a pressure build-up and oil pushing out the top vent into air cleaner and anywhere/everywhere else it could- i.e. valve covers is a good starting point.

Is the exhaust burning the whitish smoke or burning off whitish smoke-i.e. burning off exhaust somewhere? Excessive white smoke may also be a rich A/F mixture- not oil. Do the compression test and also check to see if oil has gotten the old 'chocolate milk' effect. Go from there...

earlysecond · 12-08-2002, 09:15:00 AM

I went thru 3 electric chokes on a 229 in a '81 maro until the whole drivetrain became a true boat anchor. Hopefully you have it figured out by now. 350's are plentiful, cheap and very versitile!

81Baby · 12-11-2002, 09:15:00 AM

The exhaust was producing the smoke, but there was some burn off too. With a new PCV, the smoke seems to have gone away, and I am guessing the oil leak was coming from the valve covers and just burning off the exhaust manifold so I never saw it.

The stalling problem is still there, but now my son is telling me that the car only stalls within the first 5 minutes or so. It does not stall when first started, so it seems to me that when it is cold, the choke closes properly, and slowly opens. I have verified this to be true. I am guessing that the engine only stalls within a few minutes of the choke first opening, so it is just not fully warmed up yet. Maybe a temperature sensor is bad, so the computer is not setting the mixture correctly. Anyway, once the car has been driven for 10 minutes or so, it does not stall anymore. I need to get it out myself first thing in the morning to verify this data.

We will check the sensors, but we can live with this until that 350 is ready. We don't want to spend another dime on this slug if we can help it.

Thanks for all of the help.