2003 Bonneville SSEi: Bad LIM Gasket?

[Antarctico]

I don't put many miles on my 2003 SSEi (about 65K miles on the odometer), and after sitting for a couple of weeks undriven, it has developed a ticking lifter when cold (which goes away when warm). While diagnosing this problem, I noticed condensed coolant (it tastes sweet) under the oil filler cap and in the lip of the oil filler tube. Also, I have been noticing I have to add a cup or two of water to the coolant overflow tank every two or three months, but with other things to worry about, I kind of shrugged off the slowly missing coolant. My oil looks clean and clear, no milkiness, but while the car is warming up, if I take off the filler cap and take a whiff of the filler tube, I can smell the sweet smell of coolant.

So I'm thinking the Lower Intake Manifold gasket is failing, or alternately the cylinder head gaskets, or am I just being paranoid? Anyone have any thoughts to share?

[gonzo4191]

some condensation on filler cap is normal if it only sees short trips. you shouldn't lose much coolant, have you looked at the base the supercharger for puddles with the cover off. sounds like a lim problem. head gasket problems are rare on the 3.8

[Antarctico]

some condensation on filler cap is normal if it only sees short trips. you shouldn't lose much coolant, have you looked at the base the supercharger for puddles with the cover off. sounds like a lim problem. head gasket problems are rare on the 3.8

I pulled the plastic engine cover off this morning and I did find a clear, thick, orange syrup of congealed coolant at the base of the supercharger (the end pointing toward the air box) along with several spinners from my backyard maple tree -- man those things get in everywhere! Thanks for the info on the head gaskets. It's comforting to know problems with those are rare on these engines. Thanks for helping!

[J Wikoff]

It sounds like new LIM gaskets might be a good idea.

[tkh2000]

Do you use any RTV on the valve cover gaskets and the upper intake

[Antarctico]

It sounds like new LIM gaskets might be a good idea.

Yea, it kind of looks that way. The car is ten-years old, so I can't say I'm surprised -- plastic gaskets are only going to last so long.

So, now the next issue I have to diagnose is the loud, metallic, ticking noise at start up. I broke out my mechanic's stethoscope and, for the life of me, it sounds more like one of the injectors might be the culprit, but since it only does it when the engine is cold, I will need to take another listen. One other odd thing, when the noise is at its loudest, the idle is ugly rough -- clearly one cylinder is not happy. After the engine warms up, and the noise goes away, the idle is smooth as the day I bought the car. Very weird...

[Antarctico]

Do you use any RTV on the valve cover gaskets and the upper intake

Sorry bro, no upper intake manifold on my Bonneville as it is supercharged, but in the videos I've seen where there is valve/lifter work done on these 3800 engines, I have not seen anyone use RTV on the valve cover gaskets. The factory gaskets are rubber of some sort, not cork, so I can't imagine using RTV on them would do anything but make the job extra messy.