Ok, issues here with my '98 3800. A few weeks ago, started noticing the motor was losing coolant (had to refill every 2 weeks) but there were no obvious external leaks anywhere.

Shortly after this issue came about, the lifters began tapping loudly at startup but would go away after warmup. Changed the oil, lifter problem disappears for about 1500 miles, oil appears runny, but does not have the "milkshake" look to it. Oil is Mobil 1, coolant is Dex-cool.

Now could this be a leaky head gasket causing coolant to leak into the oil killing viscosity causing the lifters to tap? Besides a cracked block or head, are there any other gaskets that could be leaking coolant into the oil?

 

verry possible, does it smoke on startup?


Don

 

have heard alot of the lower intake manifold gaskets causing troubles on the 3.8's

for your case if you think it is a head gasket it's probably best to run a quick compression test; if your head gasket is going you tend to find that individual cylinder having lower than normal compressions.

personal opinion is if you think it is a gasket going it is much cheaper to go ahead and pull it apart and swap out the gaskets as preventative as it is better to be safe than sorry, but thats just my 0.2

best of luck

 

No smoke, no visible leaks, no external signs whatsoever.

I have heard of this issue in W-body L67 3.8's with the plastic intake manifolds but never heard of an issue with the F-body 3.8's intake manifolds. Anyone else heard of this problem on F-bodies?

Thanks for the replies guys, I'd love for it to be something other than a head gasket but so far not looking too good...

 

Yea my 3800 had problems w/ the lower intake gasket, on cyl #3 was my missfire

Don

 

I have what sounds like a faint lifter noise, but only under load. Still trying to figure it out.

But with your situation, do the compression test like previously posted. Then take it to a radiator shop and have the system pressured and wait for a leak-down. I would probably pull the thermostat beforehand and run it a few days to be sure the thermostat housing is not leaking after removing the thermostat.

Either before or after the above, I would also pull the oil drain plug on a "overnite" cold engine and watch the first few ounces of fluid...catch it in a tin can. Since water sinks in oil, if there is any water, it condensed overnite and should be the first to come out. Don't toss that fluid...compare it closely with some fresh Mobil-1 for any signs of water being dissolved. Might even get some fresh Mobil-1, add a few drops of coolant, shake it up and let it sit before comparing to your engine sample.

My point is that we all know what the green coolant and oil looks like..milky. But I wonder if the orange coolant responds the same way? Check it out and let us know.

You're right, the coolant has to be going somewhere.

Wishing you a cheap fix..