Good compression, thick white smoke.

[MrGriff750]

My 1G FWD 91 is billowing smoke out of the exhaust and i can also see smoke coming out from the exhaust manifold. I have good compression numbers on all cylinders. Also, I had the radiator cap off when i started the vehicle and coolant shot up out of that point. I let it run for about 15 minutes and air consistently was bubbling up through the radiator. The only time it didn't bubble was when the thermostat opened up and it sucked all the coolant down. From within the vehicle, I noticed the temps go up and the heat would quit working for a time, until i gave it throttle and (what i assume) get past the air bubble by the thermostat.

Here's a bit of history on the engine. The timing belt broke a while back and some valves got bent in the process. I bought a freshly machined head that was decked. Slapped the head on with a new head gasket and it drove fine with no issues until this started to happen. I admittedly forgot to re-torque the heads after 500 miles. I torqued them to 85 now, and the compression numbers are still good.

I've read that it could be many things. Head gasket, turbo, fiav seal, clogged pcv line,.....but I wanted people to see my situation specifically and possibly offer a better diagnosis to my scenario.

Thanks for taking a moment to read this.

 

[Jermoturbo]

Sounds like you need a new head gasket. The bubbling over of coolant is from excess pressure in the coolant system, a root cause of a blown head gasket, along with the white smoke.

 

[MrGriff750]

Sounds like you need a new head gasket. The bubbling over of coolant is from excess pressure in the coolant system, a root cause of a blown head gasket, along with the white smoke.

That's what i'm fearing. I just want to eliminate any other possibilities before i jump into the head.

 

[BogusSVO]

How was the head surfaced and what head gasket did you install?

 

[eDeclpse92]

I had the same exact problem on a previous motor. It was the head gasket. This was on a 4g63 N/T however but the symptoms were still the same.

 

[MrGriff750]

How was the head surfaced and what head gasket did you install?

I used a metal Felpro gasket. I bought the head off a guy who had it done, but i don't remember specifics about it.

 

[BogusSVO]

I used a metal Felpro gasket. I bought the head off a guy who had it done, but i don't remember specifics about it.

Well that could be the whole issue, MLS head gaskets are very picky about the surface finish they seal too.

Even if just one of the 2 sealing surface is correct, they still can have issues.

That is why it is said that both the head and block need to be surfaced.

http://www.dsmtuners.com/forums/new...face-4g63t-cylinder-head-mls-head-gasket.html

http://www.dsmtuners.com/forums/cyl...-deck-4g63-cast-iron-block.html#post152790451

Depending on the HP level, and boost amount, Under 500ish and 30ish of boost.

I would suggest that the head surface is checked to make sure it was not belt surfaced.
http://www.dsmtuners.com/forums/cyl...0613-why-not-let-your-head-belt-surfaced.html

Also move to a composite head gasket, either an OE Mitsu or a FelPro 9627PT

A composite gasket is more forgiving on a improper, irregular surface than a MLS

 

[MrGriff750]

Funny, I was just reading up on some of your tech posts about this. I'm guessing the only way to surface the block is removing it from the car, and I really, really don't want to do that.

Also, I just realized that it's a Topline head gasket that I installed. It came with a set of gaskets for a rebuild.

I'm planning on checking the cylinder head and block surfaces for flatness myself. If the head needs work I'll probably take it down to a local machine shop to have it resurfaced. I'll make sure they don't just belt sand it.

I forgot to mention something initially.

Like a dummy, I didn't re-torque the head bolts after i drove it a short time. So I probably put around 2k miles on it since then.

I'm sure that was the cause.