Good morning! (or afternoon, depending on your time zone)
I stumbled on this venue while doing a google search about slight coolant loss on my '07 Lacrosse and it looks like a good place to hang out, learn and even contribute. I've been working for GM Dealerships for over 40 years, mostly Buick and Pontiac, going back to the days when the factory fix on a 3.8 liter with the oil light flickering at idle was to replace the 10 psi. oil light sender with a 7 psi. replacement. For the recent past years, I've been with Chevrolet, so my 3800 exposure has been minimal.
My question concerns coolant loss on my '07 Lacrosse. A few months ago, one of the coolant elbows failed and I had an overheat condition until I could get it safely off the road (less than a mile). After replacing them with the aluminum ones, I ran straight water for a while, just to verify there were no other leaks. After I flushed and refilled the system with DexCool, I noticed it using about a pint of coolant per week in my normal commuting cycle. The oil fill cap had random spots of the dreaded foam, but none on the dipstick and no increase in oil level. No unusual smoke from the tailpipe and no coolant odor is noticed either, nor is there any loss of performance or idle quality.
I haven't had the opportunity to get it in the garage for coolant pressure and compression tests yet, but will ASAP.
Based on my searching here, I'm thinking lower intake gaskets are a likely area for leaks, as they would possibly leak into the lifter valley, rather than into the combustion chamber. I've never done a LIM removal before on a 3800, but it doesn't all that difficult, since I've done a few uppers in the plastic manifold days of 3800's and a bunch of Chevy intakes in all the years I wrenched on Winged Sprint Cars.
Obviously, some testing is in order before I start loosening bolts, but does it sound like I'm on the right track?
Thanks in advance for your input.
Bill
I stumbled on this venue while doing a google search about slight coolant loss on my '07 Lacrosse and it looks like a good place to hang out, learn and even contribute. I've been working for GM Dealerships for over 40 years, mostly Buick and Pontiac, going back to the days when the factory fix on a 3.8 liter with the oil light flickering at idle was to replace the 10 psi. oil light sender with a 7 psi. replacement. For the recent past years, I've been with Chevrolet, so my 3800 exposure has been minimal.
My question concerns coolant loss on my '07 Lacrosse. A few months ago, one of the coolant elbows failed and I had an overheat condition until I could get it safely off the road (less than a mile). After replacing them with the aluminum ones, I ran straight water for a while, just to verify there were no other leaks. After I flushed and refilled the system with DexCool, I noticed it using about a pint of coolant per week in my normal commuting cycle. The oil fill cap had random spots of the dreaded foam, but none on the dipstick and no increase in oil level. No unusual smoke from the tailpipe and no coolant odor is noticed either, nor is there any loss of performance or idle quality.
I haven't had the opportunity to get it in the garage for coolant pressure and compression tests yet, but will ASAP.
Based on my searching here, I'm thinking lower intake gaskets are a likely area for leaks, as they would possibly leak into the lifter valley, rather than into the combustion chamber. I've never done a LIM removal before on a 3800, but it doesn't all that difficult, since I've done a few uppers in the plastic manifold days of 3800's and a bunch of Chevy intakes in all the years I wrenched on Winged Sprint Cars.
Obviously, some testing is in order before I start loosening bolts, but does it sound like I'm on the right track?
Thanks in advance for your input.
Bill
