hey guys... i have been having this problem for about a year now..... i skimped out on buying new valve guides for my iron l98 heads..... but had a 3 angle valve job done on them with manley springs retainers and screw in studs along with new steam seals..... i was wondering would stock 180,000 mile valve guides cause blue smoke come out the tail pipes.. it does it on start up and at idle.. its not very noticeable but when you rev the car and look back you can see see some very light blue smoke... the New engine has about 20,000 miles.... did a compression check and its very good... oil pressure is excellent and runs very very strong.... so my only conclusion can be worn out valve guides.... this would be an excellent excuse to step up to afr heads.. any tips would be good...

 

guides could cause the problem or seals...did you put new seals on after the seats were cut?

 

Yes.

If you pull some plugs you should see that one side of the porcelain is darker than the rest, perhaps close to black. That would be the side of the plug that points at the intake valve, where the oil is coming in. Usually the threads will be wet with oil as well.

If it's rings the whole center electrode will be pretty much evenly coated with oil/carbon but the threads will usually be dry.

 

the spark plug wires are a nice caramel color last time i check i dont remember seeing any kind of black but im not sure... i will have to check that tomorrow..... yes the seal were replaced about three years ago... but two years ago i had the heads off again and took the heads to the machine shop and had headwork to handle the gm hotcam and reused the same seals i had back when i was running my old l98 block with the crane 2032 cam..... the old engine was spinning at 6 grand on the dyno and spung bearings... i dont know if that could have also ruined the seals that i had in the heads...

 

you found a shop that would do a 3 angle job but not require new guides? Are you sure that someone didn't just lap the valves for you?

 

im not exactly sure what they did.... i know that the original valve guides were still in there...... either way i hope it is the head because they are coming off soon for better heads..... i will pull the plugs and let yall know what i see...

 

Is it possible with your new valve job you created more compression than previously causing blow by? Valve seal leaking will cause smoke at start up, but blowing smoke sounds like it warn rings.

 

i cant be the rings because they are brand new moly rings that have been gapped accordingly..... they dont even have 20000 miles on them..... im only running 9.7 to 1 compression with my build and run 93 octane gas.... the heads have been resurfaced... they havent been milled so even if it did change compression slightly its not enough to cause blue smoke.... like i said i did a compression check and all cylinders are within 10 percent of each other...

 

Ok I should have re read the thread. If it's not too bad just drive the **** out of it, and don't let it get to you. I need seals on my IROC, but I don't feel like dishing out the cash right now, and I have a so what attitude.

 

yea im not really to worried about it but it just started to bother me a few days ago..... i had those heads off twice doing work to them...... next time they are off they are going in the trash.....

 

well i just checked the spark plugs.... on side is definitely darker on one side compared to the other some side are almost black like you described.... but the threads are dry though....