I need some help. I recently replaced my water pump due to a leak coming up shaft of water pump (145K miles on C5). By the time I had noticed the leak I only had 1/2 gallon of coolant left. The highest the oil temp got was around 125 deg F. Since the water pump replacement I have noticed one of my spark plugs sounds airy (misfiring) and I do believe my exhaust has a whitish steamy tent.

It has been one thing after another lately. I did a Block-Chek with the blue dye and it came back negative. So, i'm thinking that I'm getting coolant in cylinder #6, but not exhaust back into the coolant system. The spark-plug/cylinder that I think is suspect is on the passenger side (3rd from the front).

I was looking for a coolant/block diagram in color to see where the coolant flows. I would hate to replace all the injectors and gaskets and a bunch of other stuff only to find out the block is cracked rather than just gasket leaking.

If I decide to replace the gasket, should I:
1) Do compression test right now before I take it apart? I don't want to hurt the engine more by running it. Don't you need a warm engine for compression test?
2) Replace injectors, timing belt, and anything else?
3) Is a gasket replacement really really difficult?
4) Should I get the head checked out by a machine shop after I get it apart? (Kinda expensive to get it towed both ways, but I would if you guys think I need to.)

Also, does anyone like Bill or any of you other guys who have done so well writing up fixes have a head gasket replacement procedure?

Thanks everyone! So far because of this forum I have had the knowledge to:
clean ignition switch, clean grounds, replace starter, replace water pump, and replace belts. There isn't anything like this place anywhere!

 

You only had a 1/2 gallon of coolant in the system, and you never noticed an increase in operating temperature...let alone overheating?

 

The temperature never got above 225 with normal operation around 220. I think most of the coolant was lost on the driveway while diagnosing the leak itself.

 

If you have constant steam coming out of the exhaust AND a cyclinder compression test indicates a leak, then you have no choice but to pull the head(s). The maintenance manual has all the information and torques you'll need, plus the specific needs to access. If the offending cylinder is on the pasenger side, its easier. Drain the coolant and oil before taking it apart and examine both for contamination. Now before taking it apart, know that you'll need new gaskets of course and new head bolts as they are NOT reusable. One item to save you...before putting it together, insure you suck out any coolant or oil from each and every head bolt hole BEFORE putting the head bolts back in. Follow the torque guidelines exactly and know that only the first go is to a torque value. Everything past that is by degrees of turn.

 

THIS !

i heard this on my coolant boiling engine also.
is this when you press gas with open hood and hear it like some air or something is going out ?

 

Yours sounds like a vacuum leak...check the air-bridge, pcv valve connection tube and pull your codes. Could be just a bearing on the idler.