Thread: '03 GTP Engine Questions: Oil and Coolant Temp

Hi all -

I just picked up a 72k-mile '03 GTP. It runs and drives great. The previous owner replaced a ton of parts in September of last year, including valve cover gaskets, oil pan gasket, coolant temp sender and thermostat. So, I have a couple of questions.

1) I smell oil. It's not leaving puddles, or even a drop on the ground. It's not enough to smoke either but I can smell it. Are valve covers a common place to leak? Or could it be somewhere else. Wherever it is, it must be leaking onto the hot exhaust.

2) According to the gauge, it's running cool. It's midway between 160 and 210, which I calculate to be around 185 degrees. I looked up the part number for the thermostat and it's 195. It gets a bit warmer if we let it idle for a long time in the driveway, and the fan kicks on like it should. The heat is hot enough. Coolant in the overflow tank is a bit low, but not alarmingly so. I plan to top it off later today - I'm letting it cool down now so I can make sure there's actually coolant in the radiator. I assume there is since I have heat. Is 195 the stock thermostat temp? Are the gauges accurate? Where should the needle be sitting?

Having owned a few GM products from the early-2000s, I'm not surprised by some of the other quirky things with it. Overall it's in awesome shape and actually rides nicer than my 2017 Charger.

Thanks!

Thanks! He also replaced all of the hoses and elbows, so he (or whoever did the work) may not have burped it properly. There was coolant in the radiator, so I topped off the expansion tank. Took about a quart to get it to the full hot line (though it wasn't really hot - kinda lukewarm).

Originally Posted by mguzzo

I don't use the cluster temp gage except as a reference. I watch it come up as the engine warms up then it will take a dive as the thermostat opens up. Other than that if the temp is holding steady I don't worry about its accuracy.

It is behaving like it should. Warms up a bit when idling, fans come on as they should. Temps stay steady when driving, creep up a tiny bit at a light and go back down once I start moving. I guess I won't worry about it. I got a cheap OBDII streaming tool just for fun. I always wanted one anyway. All I have in the toolbox currently are code scanners.

Originally Posted by Fivefingerdeathpunch

The first big line between 160 and 210 is 190-195 degrees, it was the same way on my car. It always stayed right around that mark. Not something to worry about like you said.

If you can't find the oil leak/seep. Try degreasing the engine with some purple power or simple green, wash everything off to remove any oil films. Drive it around for a day or two and start checking over everything to see if you can find any new seeps/leaks.

Cool - I won't worry about the temp then.

The guy had the thing professionally detailed before he delivered it yesterday. You can eat off of the engine compartment. I need to wait for it to accumulate some more. I can see the front is not leaking. The back is harder to see but I do see some residual oil that they didn't wash off on the back cylinder head. I'd guess that back valve cover is leaking. Maybe they got lazy and only replaced the front one because it's easy.

Originally Posted by Scottydoggs

maybe he de greased it and what your smelling is the de greaser burning off still. can take a few days to go away sometimes.

I thought/hoped that too. It oily but not distinctly sharp smelling like oil. So it may burn off. He replaced the entire exhaust system from the manifolds back, too, so there might be some residual stuff burning off of that, too.

Well I figured out what I was smelling. It's a combination of oil and antifreeze. The intake manifold gasket is leaking. After doing a search it seems that it's a pretty common problem. Not too hard to fix, but it would be easier without the supercharger. Rock Auto had the best prices. They had the Fel-Pro gasket set for $11 - the same one Advance had for $44. I got a plenum gasket too. Probably will get to it next weekend.

Originally Posted by turbojimmy

Well I figured out what I was smelling. It's a combination of oil and antifreeze. The intake manifold gasket is leaking. After doing a search it seems that it's a pretty common problem. Not too hard to fix, but it would be easier without the supercharger. Rock Auto had the best prices. They had the Fel-Pro gasket set for $11 - the same one Advance had for $44. I got a plenum gasket too. Probably will get to it next weekend.

Lim gasket was my very first thought with temp flux and the smell of oil with no leak.

It’s no different with or without the supercharger to be honest, you just take an extra belt off.

I usually spend the money on the ac delco aluminum gaskets for the lim. Just don’t get plastic ones. And since you’ll be draining the coolant you should switch over to the green coolant and get rid of the dexcool if the other guy didn’t already.

I got Fel-Pro's "2nd Design" which appear to be metal. The FedEx guy is bringing them this afternoon so I'll know for sure then. What's the issue with the plastic ones?

The coolant is still DexCool. I topped it off with the green stuff, but to your point when I drain and refill it I'll use the green stuff.

If you mixed dexcool and green coolant you’re going to get a sludgy mess. When you do switch over be sure to do a good flush to get all that crap out of there

Originally Posted by mguzzo

If you mixed dexcool and green coolant you’re going to get a sludgy mess. When you do switch over be sure to do a good flush to get all that crap out of there

I used a Prestone product that is supposedly compatible with Dexcool. I'm draining it this weekend anyway.