Valve stem replacement 2001 GT

Oct 26, 2017

Well I have noticed oil burning when idling for long periods of time, long sits at lights, only when hot etc. If I hammer it down and drive the "blue cloud" clears up and im good until I idle again for a bit. The driver side head had a valve job done by the previous owner when he had a spark plug eject on that side (he replaced the head) so Im assuming those seals are good still. I am also assuming I only have to replace the passenger side valve stem seals. My computer throws a code on the passenger side (Bank 1 Sensor 1) for it being lean. From some other posts I read that too is a symptom. Also the bulk of the smoke seems to come out the passenger side tailpipe. I also pulled the PVC and let it idle for a while too. Same issue with the blue smoke.

I have bought the OTC 7928 Ford valve spring compressor to do this job. The motor will be in the car for this because I have no way of taking it out of the car. Has anyone done this before with the motor in the car and the cam still in the head? If so have any valuable tips? It seems like, just from staring at my motor with the valve covers on, that its going to be tricky once I get near the #2 and #3 cylinders because of the tower being there.

My plan is to crank each piston to TDC before I start on the corresponding valves so the valve has no way of falling through. This would mean I dont have to worry about compressed air tools, rope etc. Would this be a fair assumption?


1999 Mustang GT with 2001 Mustang GT motor (Romeo)
very lightly modified. (CAI, Underdrive pulley, 75mm upper intake and TB, new ford Lower intake, EGR delete)
93 octane tune from Bama.

So in a nutshell:

Doing the work:

1. Anyone done this before with the motor still in the car and have any tips?
2. Does my piston TDC positioning idea make sense and will work?
3. #2 and #3 cylinders going to be an issue with the tool mentioned?
4. How long does this normally take to do?

Saying skip it and not doing the work:

1. Will this type of leak cause any other issues or bring on more serious issues if left alone?
2. Would you recommend just dealing with the occasional smoke issue instead of fixing it?
3. I have a 93 Octane tune. Will leaving this alone cause any timing or predetonation issues?
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Mustang Master
Nov 6, 2016
How many miles on the engine? High mileage engines can have worn valve guides too, negating the benefit of new seals. Here is a good article:
I have done many but none on the mod motors yet, if nobody chimes in I do have the Factory Shop Manual as a last resort. Have you tried YouTube for any good videos?
Oct 26, 2017
Motor has less than 100k on it. Searching on youtube gives me various results but none that really show what I need to see. You do see people doing the work but not any really in the manner I am looking. You find people working to remove the valve stem seal with the cam in but the motor is on a stand or they have the head sitting on a table.

Googling and looking at forum replies you find people who say they have done it before or in the process of doing it with the motor still in the car. However they end up usually going on a tangent about some "badass" cam they are thinking about installing while they are there then everyone hands out virtual high fives. They never follow up with any things to watch out for, videos, or success/fail stories. I was hoping someone here has done it before and could answer those questions I had above.

I thought about valve guides being a potential issue but, short of a compression test, I am not aware of any other easy way to tell.
Oct 26, 2017
It doesnt smoke at all on cold start up. Motor sounds fine. Once it gets to operating temp (about 15 mins idle) you will start hearing some light random chirping which sounds like maybe a pulley (I know my AC is going out as it has yellow oil leaking out of the compressor so I often blame it for the noise) or could just be something like a motor mount. The "chirp" tends to go with the shake of the motor. Normally it idles fine really now that it has this tune from Bama.

When its warm is when the oil smoke is displayed that I mentioned above. I can let it sit and idle and then rev it up then you will see a blue cloud. It will clear out if I let it rev. Then it doesn't do it on subsequent revving unless it let it sit and idle for a few mins.

Only time it does this is honestly if you let it idle too long. This could be at a traffic light that lasted eons or if I roll about a quarter mile or less under its own idling power (cruising through my neighborhood in 2nd under idle power because we have young kids who play in the street). My wife saw a very small puff of smoke after that.

Really it doesnt happen often at all under normal driving conditions. I have to make it do it by idling for a while and then revving etc. I think I lost maybe slightly less than a half quart of oil over 1k miles. But there is also a slight leak around the oil pan too cause I notice the oil but maybe one drop hits the ground. That will be fixed whenever this motor gets rebuilt or unless the oil all the sudden starts leaking a lot out the pan seal.

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