smoking every now and then

[Craig]

I have an 89' Sho. I just had a seal job done recently - cam seal, valve stem seals, spark well gaskets, and valve cover gaskets. After the job, the car ran real good. But the car smoked up every once in awhile. The mechanic did a leak down test, decided that the valve stem seals had a seating problem, and redid those. Another leak down test indicated the new seals were tight. Again, the car is running good, but it still smokes up every now and again. He does not see any external dripping. Can someone talk about what might be causing this.

Thanks,
ct in Kentucky

 

[yaycandy]

How much smoke? A puff or enough to smoke out a garage. If you still have cats they can hold moisture and will smoke off pretty quick.
Oh also oil or coolant from it leaking a bit before can take awhile to fully burn off in a cat or in the manifolds. Id drive it and keep an eye on the fluid levels. It should stop then, im sure the engine puts out some serious heat at high rpm with 9.8:1 compression and high octane gas so it could take a bit for it to burn it off completely.

 

[Craig]

I've just gotten it back from the valve stem seal redo. It does not smoke all the time. It just happens once in a while. For example,
on a 10 mile trip, it might smoke up 3 times. Sometimes its just a smell with no smoke. Sometimes the smoke up is small. But 1 of the 3, if I were in the garage when it happened, I would walk outside.

Its smoking much like it did before the redo. Its like oil pools and then drips, hits and overwhelms the cats, and smokes. The mechanics tests tell him the seals are seated correctly after the redo. Maybe there is more than 1 problem with the same symptoms.
The symptoms before the redo were high oil use and sometimes it smokes.

I will be watching it. The mechanic mentioned he had read about a 'pan' situation that had the same symptoms but needed to find out more. Does that ring a bell with anyone?

 

[yaycandy]

Yea this one could be rough to figure out. Not much room under the hood and amazing intake to watch for oil spots. You could let it parked somewhere to see if its leaking underneath when parked or running. A large pan under it will help you know what fluid but its probably oil. Could also be power steering fluid. Maybe you have a leak at a hose and could leak worse when its pressured the right way when turning. Lots of things to check. Even could be oil cooler

 

[Craig]

I have card board on my garage floor. We know about a very small oil pan gasket leak of a drop every time I pull into the garage and park the car for awhile. That leak under pressure is a ? The first time after the redo it had a substantial smoke up, the road had no grade and I had very slowly coasted up behind another car at a light so there was little momentum.

I've always believed things like this can always be fixed. I'm beginning to wonder.

 

[NoSlo]

Are we talking about smoke out the exhaust pipe (probably no) or smoke from oil burning on the cats (probably yes) and engine bay? Cats burn the leaking oil only when they get hot, and they get hotter going uphill slowly for a while. Front 60k is supposed to fix this oil-burning leak, not cause it.

If the latter, and the mechanic concluded valve stem seal, then you are stuck with a bad mechanic...

More likely that one of the seals was not installed properly or was damaged (or one of the cams or crank was scratched). It didn't leak before but now it does. The "oil pan gasket" leak drip when parking is almost certainly not a leaking pan but where the front seals leak out of behind the timing belt cover. If it wasn't for the symptom emerging only after "service", we might instead fault the oil pressure sensor or such.

Ask him to show the cam seal expander tool or the seal installer required by the shop manual...

Valve stem seals instead are a puff of smoke out the tailpipe when starting the next day.

 

[Craig]

The smoke is out the exhaust pipe. There is a black residue in the pipe. It does not smoke all the time. It just happens. Its like oil pools and gets into the exhaust unburned, hits and overwhelms the cats, and smokes up. Its not something outside the exhaust pipe dripping on the pipe. I'm not a mechanic.

He had just finished the cam seal, valve stem seals, spark well gaskets, and valve cover gaskets. Oil in the cam shaft position sensor destroys timing. The spark well gaskets and valve cover gaskets were tight. And a test he ran suggested that one or more of the seals was not installed properly, didn't seat, or was damaged. So he redid them with a new seat of seals. He feels like the seals and gaskets are good now and the car runs real well. Whatever is causing the oil to leak into the exhaust is not impacting how the car runs so far.

The car was using a quart of oil every 400 miles before the seal job, but the car had lost timing, was leaking oil in a couple places, and was not running. Initially, after the seal job, oil use looked like it was on the way to a quart every 1000 miles. But then I had my first smoke up and the oil use went to around a quart every 100 miles. It was like something had failed.

This is the 2nd major job this mechanic has done for me. He has brought the car back from the dead twice. The 1st time was a decentegrating crank gear. This time it was past time to do some seal/gasket work. He is highly thought of in my area and honest.

Where could that oil be coming from?

 

[rubydist]

It is not smoking out the tailpipe from valve stem seals. On this engine, with the way the shim cap fits over the top of the valve stem, they use almost no oil even with ruined valve stem seals. I have taken apart engines that did not smoke and the exhaust valve stem seals were all totally gone (all the rubber was gone).

What you are describing is much more likely that there is enough oil in the "oil separator" that in certain cases (how you turn or the angle of the car) it will **** some of that into the intake and cause it to smoke. A catch can is a very good idea anyway on this engine.

 

[Craig]

rubydist, what is the oil separator and what is a catch can? What you described is whats happening. Again, I'm not a mechanic.

 

[rubydist]

Modern emission controlled engines do not vent crankcase pressure (blowby) to the atmosphere, they recycle it into the intake via the pcv valve (positive crankcase ventilation). On the SHO engine, that is different from many engines in that it consists of a hose to a rectangular enclosure (oil separator) under the intake manifold that is supposed to separate out the oil so as to minimize the amount of oil ingested by the intake. This does not work as well as it might, as the oil separator tends to collect a good amount of oil, some of which can get sucked into the intake in excessive amounts in certain situations. This can be improved by installing a catch can. The catch can is designed in such a way that the blowby and oil mixture enters the catch can and the flow takes a sharp turn, which tends to separate the oil out of the mixture and allow it to be captured in the can rather than being sucked into the engine. In the SHO engine, the catch can should be installed before the oil separator. If you search online for "catch can" you will see examples of what this is and how they are installed.

 

[Craig]

rubydist, thanks for the explanation. I have an engine book someone sent me recently for the 1989 Sho which is what I have. Pages 118-119 discuss positive crankcase ventilation and have some pictures. I'm thinking the oil separator should be cleaned out and hose and valve replaced? The car has 160K miles on it. Its been maintained pretty well, but lately I've put a few things off until I saw how this seal stuff went. I have real good people I hire for mechanical, body, and interior work now. My mechanic is not a Sho specialist of course, but he knows more about my car than anyone in my neck of the woods. Its a learning process for us all all the time I suppose. My hat is off to the many skilled people I depend on.

 

[FastCAD]

I have an 89' Sho. I just had a seal job done recently - cam seal, valve stem seals, spark well gaskets, and valve cover gaskets. After the job, the car ran real good. But the car smoked up every once in awhile. The mechanic did a leak down test, decided that the valve stem seals had a seating problem, and redid those. Another leak down test indicated the new seals were tight. Again, the car is running good, but it still smokes up every now and again. He does not see any external dripping. Can someone talk about what might be causing this.

Thanks,
ct in Kentucky

The crank seal can leak onto the cats causing intermittent puffs of smoke and drift the smell up into the cabin. Check behind the crank pulley to see if it's dry.

 

[Craig]

Yes, I have had the crank seal done. It was pinched and had a small consistent leak. I think the crank seal is OK, but thanks for the reminder.

I'm thinking the oil separator should be cleaned out and hose and valve replaced and a catch can installed in this work? What do you all think? Is this a big job? And does the catch can have to be emptied every so often?

 

[rubydist]

Yes, the catch can needs to be emptied from time to time. Its not a difficult job to do, except that the hose to the oil separator will likely be hard as a rock from being roasted for 20 years, so it will be hard to get off.

 

[Craig]

rubydist, I've had this model vehicle since 1990 as a daily driver and I've not encountered this spill off/smoke up problem until this seal job. I'm guessing that the oil separator works less effectively as the vehicle ages, and that it was just a coincidence or that the smoking started when it did when something got distrubed in the seale job. What happens with this PVC process as it ages? Does the separator fill up with sediment, and if so, can it be cleaned out? Does the hose diameter narrow? Does the PVC valve not function as well?
I would just like to understand how this PVC process of this vehicle model gets to this spill off/smoke up point a little better. Thanks rubydist and everyone for your time.

 

[rubydist]

The catch can will fill with oil over time. Depending on the exact style of the catch can you obtain, they typically unscrew or unclip the "pail" from the "head" so you can dump the oil out of the "pail" part, at which point you can clean it as you wish. If you never empty the catch can, eventually it fills up with oil so the oil is carried into the factory oil separator just like it is now.

 

[Craig]

So it sounds like the catch can gets the normal to the factory separator inflow and as long as its emptied 'on time', the smoke ups should stop? Does the factory oil separator have to be drained if it can be, or just let it spill off until it doesn't spill?

The mechanic has said twice that the inside of the engine looked good. He said it came apart easy, had no corrosion, rust, or sediment, and went back together easily in both the crank gear and seal jobs. Its just interesting for me to try to understand what happens to an engine after 30 years. It will be a big deal to get this smoking stopped. Thanks again. I hope this is it. I'll mention the crank seal again to the mechanic.

 

[leolove]

Hey where can i find a set or some valve cover gaskets for my v8 sho i would really appreciate it

 

[luigisho]

Now I remember why I hesitate to buy another Gen3. You can't get those. OEM ford part numbers in this thread

Help locating Valve Cover gaskets

I was given a price quote, for valve cover gaskets + intake plenum gaskets=$300, from a buddy who works with ford and this is his cost. There has to be a source for reasonably priced gaskets I must not know about??

shoforum.com

 

[leolove]

Now I remember why I hesitate to buy another Gen3. You can't get those. OEM ford part numbers in this thread

Help locating Valve Cover gaskets

I was given a price quote, for valve cover gaskets + intake plenum gaskets=$300, from a buddy who works with ford and this is his cost. There has to be a source for reasonably priced gaskets I must not know about??

shoforum.com

Thank you!