Camaro91RS

Hi everyone I really appreciate you taking out the time to check my post. This question is for a 93 Trans Am 5.7.

I'm wondering if there's any explanation, other than a blown head gasket, for why white smoke that smells like coolant would be blowing out of the exhaust pipe? I notice that it only happens once the car is warmed up. I have no coolant in the oil, and the car has never overheated. This problem started directly after I flushed the heater core. I have to keep filling up the radiator with coolant every few days. I know this sound like a blown head gasket, but like I said the car has never overheated. The car has full power, it drives great, doesn't overheat, and there's no coolant in the oil at all. Is there anything other than a blown head gasket that would explain this loss of coolant and heavy white smoke out the tailpipe? Also, if any of you have ever done a head gasket job before - I would appreciate some pointers. I'm going to do a compression check tomorrow.

Thank you so much in advance

MachinistOne

These motors very commonly blow the head gasket to water at the back cylinder, you'll be burning the coolant but not finding it in the oil. It's due to the iron block and aluminum cylinder head expanding at different rates and GM hadn't switched to an MLS gasket yet which allows that to happen without destroying the gasket.

If you pull the heads you'll need to get them surfaced, but first check the block deck for damage.

Fatdog2

Had to mention this.I had an old nissan and we thought we blew a head gasket so we uncorked a spark plug and turned the engine over and water came squirting out at me big time though the spark plug hole.(blown head gasket).Had the head redone and new gasket put on it.I would pull # 8 plug and see if this happens,then # 7.Hope this helps.I don't see how a compression check would find this problem but am always ready to learn.

4586

If you remove the spark plugs they are normally brown in color, if you are taking in water the spark plug for that cylinder will most likely be white (from being cleaned by the hot water).

Fatdog2

I was wondering did you use a radiator flush like prestone radiator flush and how long did you leave it in the system?I'm reading different things from other car clubs that 10 minutes should be ok,but not 2-3 days as some problems may occur like eating away at head gaskets ect.Just wondering.Thanks.

Camaro91RS

MachinistOne , Fatdog2 , 4586 - Thank you SO much for your responses.


Fatdog2 - I actually used a hose on low pressure to flush the heater core (instructions on shoebox's website) In retrospect, I wish I had used something like prestone to flush the entire system because I fear the gunk being stirred up may have caused my head gasket issue.



This weekend I removed both heads. I am hoping for some feedback from the forum's members as to whether these photos depict a blown head gasket. I've never done this job before, so I'm not exactly sure what to look for. It seems to me that the left-side rear cylinder "piston head" appeared lighter in color, as compared to the other three "piston heads" on that side (it was also clean around the edges). See photos. Although the gasket was intact when I pulled it off, once it dried out, a portion of it broke off when I started taking photos (see photos). I don't see any obvious cracks in the heads and I'll clean them up tomorrow.

I have to tell you that removing these heads made me feel like I've been to hell and back. I'm concerned that I did not document precisely where the hoses on and around the intake manifold/fuel rail all go, so I may be asking for some more help from the forum's members on their proper placement once I hook everything back up.


Thank you so much for all of your help

shoebox

From what I can tell looks like leakage on the exhaust side at the back cylinder. The other side looks like it might not have been far from the same fate (looking at the head picture). The clean cylinder is definitely the telltale for leakage.

Doing the flush would not cause this. This is a long term gasket breakdown.

Camaro91RS

Thank you shoebox.

One of the forums members suggested that I needed to replace my steam pipe, which fits in the back of each head. The part number for the steam pipe for my 1993 5.7 is part number 10108635, but GM has discontinued it. GM does currently offer part number 12556260 as the steam pipe for a 1995-1997.

Would anyone happen to know if GM Part No. 12556260 would work since Part No. 10108635 is discontinued? I'm wondering if there is a way to modify it to work. GM says that 12556260 will only work for 1995-1997, but I'm not sure why.

Could someone explain why it's important to replace this steam pipe if it doesn't appear to be clogged?

Thank you so much

shoebox

You could use the later steam pipe, but you might need a little longer rubber hose to connect it to the radiator. Did you get the pipe off and see that it and the banjo bolts and head are not clogged? If they were clogged, it might contribute to more heat at the back of the head and deterioration of the gasket in that area.