My 1988 SWB 2.6 was completely rebuilt less then 10K miles ago. Included new Clear Water rebuilt head and I had installed the Starion head gasket. Also had the radiator serviced. Last week noticed problem with motor and pulled into a parking stall to see whats up. At idle just before turned the car off white smoke started to come from tail pipe. The trucks temp gauge never went over half way point but who knows if its accurate. I noticed while truck has been siting it is leaking coolant around the area where the exhaust manifold attaches to exhaust system. Question I don't have water in the oil; do I have a blown head gasket or is there another gasket that has failed in the motor to cause this problem? How would go about determining the problem? <img src="/forums/images/graemlins/confused.gif" alt="" />

Sorry to hear that. My 87 2.6 did the very same exact thing a couple months ago. The coolant leak you see is the running down the inside of the exhaust manifold.

My cylinder head (also from Clearwater with 90+ miles)developed a casting porosity leak in the #3 exhaust runner area. A porosity leak is a pin hole leak in the aluminum casting.

You MAYBE able at remove the exhaust manifold and closely look at the walls of the exhaust runners to spot the leak. The coolant will "steam clean" area around downstream of the leak.Hopefully some else has a better idea.

As a temporary fix I used GM coolant system leak sealer tablets to stop up the leak till I could schedule some downtime to replace head. Please Google "gm coolant seal leak tablet" for part numbers and more info.
When I posted about my leak someone else replied back they had the same exact issue.Please use search function to find the post if interested.

Good luck and hope you do not have to warranty out your Clearwater head. Also if your head is defective it isolated and not widespread problem.
Again good luck and hope its not the head....If its the head I hope Clearwater stands behind their warranty

Cirrus,I hate to say it but I think you nailed it. I did not have the time to tear into it so I had my mechanic tear into it. At first we thought it was the head gasket. My wrench man has never seen this problem before on the G54b motor.He said you cold stick your finger in the head and feel a stream coming from some where on the top section of the head. I had a even 200 lbs in all cylinders.I am sure its a defective head. I am going to have the head pulled and if its defective I hope clear water stands behind the head. Less than a year and 6k mile since the rebuild I have snapped one of the studs on a timing chain sprocket gear and know the possible defective head. Oh well I am getting to know the pros n cons of the G54B motor more then I want. <img src="/forums/images/graemlins/barf.gif" alt="" />

I had a crack in the exhaust port on a 2.6 once. You could hear the sizzle on shut down.

Picked up the head from the mechanic this after noon and there is a pin hole in the third cylinder exhaust port and when you pour some water in the water jacket of the head it leaks out through the pin hole. What is even more disturbing is two of the cam lobes on the cam are worn down and you can see excessive wear on the rocker arms. I called Clear Water heads where I purchased the head for $375 in 7/07 and have approx. 5K on the motor and head after a rebuild. The salesmen said the head is out of warranty but he would look at it and repair it for free if its salvageable. I will post pictures tomorrow. The only thing I can think is the rocker arm bolts or some other bolts came lose in the head on the break in. What would cause that type of extreme wear on a new head and cam? What should one expect from Clear Water?

While welding may cure the pinhole, it may not, and there may be more just waiting to corrode thru the thin. So you want a new casting, since this one is obviously faulty, and you'll reuse the valves and springs (new seals) and hardware and rockers/shafts. Get new guides.

Re the cam. Most likely an install mistake. You need to load up the cam lobes and rocker slipper and valve tip and HLA end with cam break in lube, or it will eat up the lobes. Sometimes, if you reuse a cam with a new rocker, or old rocker and new cam, the old part is already pattern worn to match it's old mate, and is quickly wiped out by the new part, once the hardened wear layer is worn thru.

That way, you are out a new cam and rockers and seals on a new casting from them, and it's a fair deal both ways.

Welcome to Clearwater Cylinder Head, Inc.

"2 Year/Unlimited Mile Warranty" ...on remanufactured heads purchased from us.
"3 Year/ Unlimited Mile Warranty" ... on all new heads purchased from us.
From their website...

I thought Clearwater had a 2 or 3 year warranty on heads.
I would also have concerns that repaired head would be prone developing additional pinholes. Sure hope this is not a widespread problem with the G54B heads.

Please post outcome of Clearwater warranty response, would be interested hearing about outcome......

Quick update on the response from Clear Water Heads. Steve at Clear Water called me today and said that I had a deffective ( pin hole in the third exhaust port) head and he is going to send me back a complete new head under warranty. I asked him why he thought I had excessive wear on two of the lobes on the cam. He told me I either had low oil pressure or I had a bad balance shaft. I replace both when I rebuild the motor. The oil pump is a new Mitsu factory oil pump. My neighbor is a old engineer an he thinks its a case hardining issue with the cam.