Can't get car to stop smoking

[Lunch_Box]

Okay so this is on my girl friends 90 TSI Talon and it all started when she snapped her timing belt. Well when it snapped it bent all of the exhaust valves at the same time so I found a head at a local shop that was suppose to be rebuilt; so I replaced the head on her car with this one. At the same time as putting on the new head I also put on a Evo 3 16G that was off my friends car. I got the car up and running and right from the get go it would smoke at idle. It didn't matter if it was after being in boost or just a light cruise when you came to a stop the car would start to smoke and then go away while the engine was under load. I thought that it was the valve stem seals just from things that I have read and heard but did a compression test first to see how the engine was doing after the snapped timing belt. Well all went good it came back 150 Psi across all 4 cylinders. Next I ended up replacing all the valve stem seals, it seemed to fix the problem for a couple days but the car started to have the same problems as before. She drove the car for a week or so since it was her only source of transportation and one time she was drving the dip stick popped out and sprayed oil all over the engine. Thinking it was the PCV valve or the rings I did another compression test, the result came back the same 150 Psi in all 4 cylinders. I replaced the PCV valve with a new one and also put her old turbo back on and took the car for a drive. Again the dip stick popped out and sprayed oil all over the engine and the car smoke the whole time during the drive not just at idle. I am fresh out of ideas. I replaced the valve stem seals, put on a known non smoking turbo, replaced the PCV valve and the engine has 150 compression in all 4 cylinders. What else can be leaking oil to cause the car to be smoking this bad? Only thing left that I can think of is the valve guides. But if was that then why when I replaced the valve stem seals did the smoking go away temporarily? Please help.

 

[No_Skillz]

How is your valve cover breather hooked up?

 

[Lunch_Box]

How is your valve cover breather hooked up?

The car is all stock except for a turbo back exhaust so the breather is just routed back into the intake. I checked the line and there is no oil in it.

 

[eclipse_20g]

May be a long shot here, but if the Evo3 you put on had bad seals and let a little oil pass into the exhaust, then it would take a while for it to burn out. It could appear the car was smoking when there was just oil burning out. BUT, thats a long shot. Maybe check the exhaust for any traces of excess oil next time you got it ripped apart.

 

[andymoraitis]

If you've replaced the PCV with a new unit (I hope it was an OEM and not some leaky thing from AutoZone) checked compression and replaced the valve stem seals and it still burns oil, I'd think that the head you put on may have cracked valve guides. It's either that or you tore one or more of the valve stem seals when putting them on.

You may want to try a leakdown test to rule out any ring seal issues as well.

Keep us posted,

Andy

 

[Lunch_Box]

May be a long shot here, but if the Evo3 you put on had bad seals and let a little oil pass into the exhaust, then it would take a while for it to burn out. It could appear the car was smoking when there was just oil burning out. BUT, thats a long shot. Maybe check the exhaust for any traces of excess oil next time you got it ripped apart.

The turbo didn't smoke when it was on my friends car though.

 

[Lunch_Box]

If you've replaced the PCV with a new unit (I hope it was an OEM and not some leaky thing from AutoZone) checked compression and replaced the valve stem seals and it still shoots burns oil, I'd think that the head you put on may have cracked valve guides. It's either that or you tore one or more of the valve stem seals when putting them on.

You may want to try a leakdown test to rule out any ring seal issues as well.

Keep us posted,

Andy

She picked it up and I am pretty sure it came from Canadian Tire, so a crappy leaky one as you put it.

I am going to do aleak down test to see if I can rule out the rings as being a problem, then I am left with the head. I was carefull when putting the new valve stem seals on the lightly tapped them with a socket and harmer to make sure they were on all the way.

So I guess I am going to have to get a Mitsu PCV valve and do a leak down test and see what happens. If it is still smoking I am going to have to try and find a known non smoking head and it better stop then.


Thanks,
Kris

 

[91turbotalon]

I'd lean on it being either a torn valve seal or a bad guide

 

[andymoraitis]

Kris,

If the PCV doesn't fix it, I'd think guides for sure. If you don't know how old and tired that head was before you put it on, I'd be hard pressed to pin it on anything else.

Keep us posted and we'll keep our fingers crossed.

Andy

 

[Lunch_Box]

Well I am heading of to my cabin for the weekend so I wont have any updates until mid next week. I am going to replace the PCV valve with one from Mitsu and do a leak down test to see what comes up. If it is the guides how hard are they to replace?

 

[andymoraitis]

I've never done guides myself, but I'm sure you could have a machine shop quote you a price on guide replacement if they're familiar with the 4G63 head. As a matter of fact, you can call some of our site sponsors like Buschur, FFWD, etc and they can give you an idea of how much they'd charge.

 

[Lunch_Box]

Little update:

She went and had a leak test done on the car and everything came back fine so the short block is okay. I put in a Mitsu PCV valve and the car is back to smoking only at idle. I am just going to say that the head I got is a POS and that is causing the problems. With all the parts that I have replaced the only thing really left is the valve guides. So I am going to have to find some time to pull the head off and get them done.

On a side note her car just recently started backing firing. It happens when you let off the gas and let the RPM's drop, a little puff of smoke comes out of the exhaust at the same time. Any ideas what would be causing that?