94VetteDropTop

I'm trying to diagnose a few issues. Just got my 94 lt1 back from a "thorough" work effort at a mechanic. Now that I have it back, the weather is a bit warmer and I've been driving it a little more, I've noticed some concerning issues. After a good 20 minute drive, and then putting around the city at low miles per hour I'll start to get water temperature around 230-232. It will usually drop back into the 220s depending on my speed. My state inspection noted the oil leak and said looked like valve cover. Recent Corvette mechanic said it was an old oil filter and would replace with a new wix. Not sure he did that though as you can see the filter is pretty dirty but Could be due to oil leak attracting dirt.

​​​​I've noticed that when my temperature is above 215 or so, I start to see lower oil pressure when in gear and stopped. I will even get check gauges light and oil pressure will basically be at 0...but car still running fine. Jumps when gas is pressed. Honestly, I drove 4 different C4s and this is the absolute best driving feeling car. I enjoy driving a lot.

I've noticed an oil burning smell and you can see inside near where the oil pressure sensor is located looks wet. Tons of oil in this vicinity. The car did have a head gasket and partial rebuild previously so parts like this could've also been done (poorly).

I don't have leaks in the garage. I've been checking and oil level is good.

Here is what the mechanic did:

1. Heat does not work, blows cold. Heater core was bypassed. Air in the cooling system. Flushed/refilled coolant and reconnected heater core after pressure testing cooling system and heater core.
2. MAF, ECU, temp sensor wiring was electrical taped, zip tied and a mess. Electronic water temp did not work in dash. Check engine light for sensor. Car needed gas to start up often. This was all fixed.
3. Oil changed but I'm not sure about this... Or I got a mess of oil spewing out. I had told them that state inspection said valve cover was leaking and he said it was a cheap oil filter causing it. But never cleaned any oil up that I can see.
4. Brakes were shot. Pads replaced, rotors resurfaced, painted red.
5. Passenger window repaired (was getting stuck going down)
6. Opti spark and water pump "rebuilt". Not sure he actually did this.
7. Need to confirm this... But transmission fluid and filter replaced. Differential fluid replaced.

Heat still doesn't work. I'm concerned about oil pressure/leak and high Temps. Temps might be normalish, getting mixed reviews.

Any recommendations for me? Start with new flush of radiator, heater core, remove air again(myself or different shop) ? probably bypassed core due to overheat previously? No leaks. Replace oil pressure sensor? How about the two adapters I've pictured that actually go from sensor to the block?

CorvetteRules

Your fan is not set to turn on until it reaches the 230 range. My 95 comes on at 229, so what you are seeing is normal. If temps start getting above that before fan coming on you can start getting concerned.

Faceman89

Are you using the needle gauge or the digital gauge? The needle gauges are way off. I always monitor my oil temp with the digital when im driving.

94VetteDropTop

Digital. Actually hit 250 last night when in McDonald's parking lot after 30 min drive. Have a shop looking at it now..

Faceman89

Oh yeah ok that's a bit worrisome. Good luck.

94VetteDropTop

Unfortunately, went through a McDonald's drive-thru last night and we got up to 250 on the electronic gauge water Guage. 260 on oil... No boiling over... But she got hot. I'm just hoping I didn't blow her up last night.

The low oil pressure comes after the car has warmed up to 220 to 230. Even if it drops down after driving in traffic, the oil is still thin from getting heated up.

I have the car at another mechanic now. They took out the radiator and sent me this picture. So far there replacing this. Ensuring proper 5w30 oil/fresh. Replacing valve cover gasket that may be leaking. Cleaning up my oil spewage near pressure sensor to confirm if new mess is made or if old. Replacing thermostat to 195 (still need to confirm which temp cutoff). Also adding some Lucas oil additive to increase viscosity a little. I'm hoping this addresses the overheating and oil pressure issues.

Faceman89

Hopefully a new radiator fixes your issue. I had PCM FOR LESS change my fan to turn on at 200. May be something else you’d want to consider.

jmgtp

Better stop them before they put that 195 thermostat in. 2 reasons - 1) a stock LT1 thermostat is a 180. 2) LT1s have very specific thermostats that accommodate the reverse flow cooling. Putting a standard sbc thermostat will not function correctly and lead to more problems.

car addict