[87BlueSupra]

I had the head on my 87 Turbo rebuilt to correct leaking valve guide seals and low compression in cylinder #5. I retested the head after assembly and now have low compression in 3 cylinders (135, 125, 120 and 150 in the rest). I went to what I thought was a reputable machine shop but now I'm not sure. Is there anything special about the Supra head that the shop may not be unaware of? Has anyone else had similar problems with a head rebuild?

 

[ma70man]

I got shafted on a head job once too. I took it back and they redid it. My problem was solved then.

 

[Poi_Dog]

Usually when they work on the Head, the valve clearences change. Did you check the valve clearence and they are within specs? Just wondering, if that may be the problem.

 

[87BlueSupra]

Yes, I did check the valve clearances both before I installed it and after I had the low readings and they were correct.

 

[Schmleff]

This is where it is nice to have a differential pressure checker but in a pinch, hook some shop air up to the sparkplug hole and listen for the leak.

 

[87BlueSupra]

Do you have any idea how much leakage is normal around the rings as compared to a leaking valve?