overflowing coolant, low oil pressure

[Tfreestyle]

quick rundown...
-Idling to charge battery
-12-15 minutes later came to car and smoke coming from under hood, I shut it off immediately. Coolant gushing from overflow tank.
-temp somewhere in the 230-240 range, not sure, didnt look at the gauge close enough unfortunately
-will restart easily but losing oil pressure at idle, holds pressure fine at higher rpms
-oil pressure at idle before the incident was around 20psi

Full story...
Well today was a horrible day. After two years of restoring my GN I finally painted it yesterday(I did start it every few weeks to move in the primer booth or just to run it). Today I had it running on the lift charging up the battery, I stepped outside for a phone call, I come back to smoke coming from under the hood. I ran over and shut the car off. I glimpsed at the temp gauge, it was in the 230 or so range I think but I had run to under the hood to see what was happening. The Coolant was gushing out of the overflow tank, it was everywhere, hugeeee like lake under the car.

The car was maybe running 12-15 minutes. About 20minutes later I try restarting the car to see what was going on, it started right up no problem but now the oil pressure will drop quickly to just a few psi at idle. I had a friend come over and we started it up again 20 minutes later, got the idle up to about 2000-2500 rpms and the pressure seemed right, 25-30ish psi. We didnt let it run for more then about 45 seconds just in case. I wanted to start it again after it completely cooled down but the battery was dead(has a bad battery) when I went back 2 hours later so I couldnt check again.

Checked oil and it looked fine, no oil/coolant cocktail. Im thinking the coolant overflow was caused by a stuck thermostat but havent had a chance to looking into it, im worried more about the low oil pressure. The engine only has maybe 2-3k miles on it, had it rebuilt at gn1 performance a few years back, used it as a daily driver for about 3 months and just a few drives here and there til I ripped it apart for restoration.

Any ideas on the low oil pressure? Im sure it can be a number of things, any tips on what to check first?

 

[Red Regal T]

I don't know, try changing the oil and cut the filter open and look for metal. If all looks OK when you get the car put back together, drive it. If you don't have decent oil pressure, but the engine doesn't make any noise, you'll have to drop the oil pan to see if your pickup is clogged. If it's not, you'll have to check visually check your main bearings. Don't know why running it to hot for 15 minutes would have affected anything.

 

[tmsbuic]

Overheating

Make sure your electric fans are coming on.

 

[toomanymodz]

I know this doesn't answer your question, but I suggest you invest in a Battery Tender to charge your battery. Idling an engine for an extended period of time, especially unattended is never a good thing.

No milkshake in the oil is a good sign. Cut the filter open and look for metal. When you drain the oil, look for contamination there as well.

 

[williambavila]

your fans are probably coming on but not on high.. bypass the ceramic block on the fans and make it come on high. also try to find a block sniffer to test for a bad head gasket.. i left my car in a valet and they thought it would be fun to joyride and blew my hg.. i found out by checking my temp and scanmaster when i picked the car up.. i was pissed .. the fans are probably not coming on high just low speed. the oil pressure will drop as it heats up if your running 5-30 your going to have 10-20lbs at idle then if it gets hot less than that so change oil to like 10-40 or 20 -50 see what happens after driving for a while.. but check those head gaskets you may have another problem

 

[williambavila]

your fans are probably coming on but not on high.. bypass the ceramic block on the fans and make it come on high. also try to find a block sniffer to test for a bad head gasket.. i left my car in a valet and they thought it would be fun to joyride and blew my hg.. i found out by checking my temp and scanmaster when i picked the car up.. i was pissed .. the fans are probably not coming on high just low speed. the oil pressure will drop as it heats up if your running 5-30 your going to have 10-20lbs at idle then if it gets hot less than that so change oil to like 10-40 or 20 -50 see what happens after driving for a while.. but check those head gaskets you may have another problem

find a strong magnet and put it on the side of your oil filter run the car for 20 min than change oil.. cul the filter open.. post pics

 

[Tfreestyle]

It doesn't sound safe to run the car with basically no oil pressure. I'm not doubting the oil thing but how would the oil go bad? It had proper idle oil pressure before the incident

 

[DailyDrifter]

The engine only has maybe 2-3k miles on it, had it rebuilt at gn1 performance a few years back,

Thats one problem

I would guess cooling fan/air in the system. Did you have the defrost on full blast to get the air out of the heater core?

 

[Red Regal T]

It doesn't sound safe to run the car with basically no oil pressure. I'm not doubting the oil thing but how would the oil go bad? It had proper idle oil pressure before the incident

Try another gauge, preferably a mechanical gauge.

 

[whitehot1]

It doesn't sound safe to run the car with basically no oil pressure. I'm not doubting the oil thing but how would the oil go bad? It had proper idle oil pressure before the incident

It could be the oil filter that is the problem.

What brand of filter are you using?

 

[johnplogii]

Two year old oil can get pretty thin, even worse at high temps, change it. To get that hot I would think the fan did not come on at all.

 

[Tfreestyle]

havent had that much time to deal with the problem. I did have it checked out and they said the fuel pump isnt coming on? the new pump just showed up today. I did find a wire that leads to the fans that got disconnected somehow so I think that is what that issue was. I picked up some new oil and a new ac delco filter to replace the fram thats in there.

 

[TurboDave]

If the engine overheated that badly you very likely broke down the oil's viscosity pretty badly which may account for the low pressure (hopefully it's that simple).

See how things go with New 20w50 oil and filter.

 

[Phoneguy]

havent had that much time to deal with the problem. I did have it checked out and they said the fuel pump isnt coming on? the new pump just showed up today. I did find a wire that leads to the fans that got disconnected somehow so I think that is what that issue was. I picked up some new oil and a new ac delco filter to replace the fram thats in there.

The fuel pump is not coming on??? WTF
The car was running correct?...pretty sure the fuel pump was coming on.

More than likely you will be ok with changing the oil and a good filter. Keep an eye on the pressure. Good luck

Bryan

 

[Tfreestyle]

ya the fuel pump not coming on made no sense to me but I switched out the pump and it started right up. Oil and filter were changed, just used the cheapest oil at kragen which was 5w30 and oil pressure is fine, no overheating. Obviously once I get it running right will change to a real oil but now there is a new problem...

it has alot of popping/backfiring at idle(I havent driven the car, only idling in the driveway and move back/forth into its parking spot). We changed out the spark plugs while diagnosing the no start issue and the old plugs were fouled out. What would the proper spark plug gap be for this car? Im pretty sure we gapped them at .040. I have to double check the spark plug wires and make sure they were put back on in the right order. Basically once it started misfiring I was tired of working on the car for the day and it was getting dark out so havent done much since.

 

[Pittsburghkid]

Not 100% on it but i'm pretty sure your gap should be at .028. If it's .040 the boost will blow out the spark. BTW william what'd that place do about their valets blowing your HG.

 

[Chuck Leeper]

Misfire could well be a cracked plug when they were changed...

 

[bmackinnon]

Proper plug gap is a tight .030".... 5w30 is NOT the right oil to have in there if you are worrying with oil pressure...

 

[Tfreestyle]

I know that 5w30 isn't the right oil for pressure issues but its enough to see if we had under 10psi before putting in good 7 dollar a bottle oil. I will pull the plugs, regap them to .030 and see if any cracked. I do think it has to do with the plugs or wires being put back properly. When we did a compression check all cylinders were approximately 140 engine cold. It's very odd the pump went out when it did but I think the "oil pressure issue" was the car was only getting enough fuel to barely stay on and was wanting to shut off.