After pulling my car out for the first time this season I have decided to dig further into the cloud of white smoke that shoots out the tail pipe when idling hot. Last season I thought it was the carb dumping fuel because I noticed no coolant loss, now I am seeing coolant going down fast and the motor heating up like it wouldn't before.

I have the fan rigged up to come on with ign. The car would never go past a 1/4 on the temp gauge and now for some reason gets to 1/2 point driving around town and then overheating on the highway. Previous owner of the car overheated it because he took the air dam off. He blew both intake gaskets and had them changed at a shop before I bought it.

Compression is all consistent at 150-155 with the exception of 1 cyl at 120. There is no coolant in the oil and the motor still lays rubber and pulls hard. Oil still looks gold more then halfway through a change. But I am certain the motor is leaking coolant into the exhaust.

I am thinking headgasket but want to get some input.

 

Have you done a pressure test on the cooling system yet?

 

Head gasket, or possible cracked head. Pull the heads, send them to the machine shop to be checked and pop some new head gaskets on. Have fun sorry bout your luck... Can verify by doing a block test to verify compression gasses in the coolant.

 

That one cylinder at 120 , How's the sparkplug look ?

When your leaking that much coolant into a cylinder , the plug will be REALLY clean as compared to the other 7 , as it will be "steam cleaned" by the coolant .......

 

No haven't done that


If its that bad I wont even bother with this old motor. It is the original L69 with around 220,000km. I do have two free engine accessible, one LB9 and one L05.

The plug was pretty clean like liquid clean almost. There is also heavy blow by coming from the crankcase breather on that side. I figured with the 120 could be worn rings. But the motor runs so well and doesn't really burn oil. I have seen engines with worse compression and nothing out the tailpipe that indicated anything.

 

My 355 engine has bolt holes on driver's side that were drilled through to the water jacket by the manufacturer, causing coolant to leak. I welded a stud on the rear one, but couldn't on the front one, because of clearance problems; threading tape eliminated the leak.

 

Interestingly enough the bill for the engine fix the previous owner got done mentions "broken bolt extraction" with a hefty charge added.

 

may as well test it for a blown head gasket.

 

Cool post thanks! I will look into that.