Normal operating coolant temperature?

I looked through the repair manual but wasn't able to find the normal operating temp of Diablo coolant. The gauge shows around 110 C (that's just a hair lower than the 120 redline, though it's never reached it). This is during normal city driving with no high revs.

 

When I get outside the car, I hear all radiator fans running.

 

What's the normal temp supposed to be at? Thanks in advance.

What's the normal temp supposed to be at? Thanks in advance.

 

Mine is always around 80-90. 110 is alarming hot.

my 6.0 did that quite a bit here in fla. some thermatstats do not open all they way as they get older. PM me if you need a thermastat as i have a NEW one w/ gasket.

Could this also be something like a water pump failure? Not exactly sure about next steps in diagnosing this...

Could this also be something like a water pump failure? Not exactly sure about next steps in diagnosing this...

 

 

Your car is running too hot. It gets to 115 outside ambient temp here in the summer and my car runs at 80. Check your coolant level first. Also maybe you have air in the cooling system. Try bleeding the system. Also make sure both cooling fans are running.This does not cost you anything.

Remember that the temp on the gauge is in Celsius so comparing to ambient isn't really a good idea haha. That is definitely hot at 110

Remember that the temp on the gauge is in Celsius so comparing to ambient isn't really a good idea haha. That is definitely hot at 110

 

I was just trying to say that even though it is very hot outside your car should still be in the 80 ish range. As far as I know Diablo temp gauges only measure in Celsius and I thought everyone that owns one pretty much is aware of that

SV to SV. 80 degrees is ideal, but not mandatory. Mine has gotten to 100 in hot stop and go. I don't like it, but it's not dangerously hot. I have:

 

Changed expansion tank cap

Changed thermostat

Bled system a couple of times

Tried water wetter

 

Still gets up there.

 

Water pump might be a little weak, but I'm not ready to go there yet.

I was just trying to say that even though it is very hot outside your car should still be in the 80 ish range. As far as I know Diablo temp gauges only measure in Celsius and I thought everyone that owns one pretty much is aware of that

 

 

Haha, I figured!

check your radiators. They are notorious for corrosion.

Mine sits rock solid at 80* regardless of the weather, are you sure both fans are kicking on?

Mine sits rock solid at 80* regardless of the weather, are you sure both fans are kicking on?

 

Both fans are running, though funny enough, the left fan exhaust (that blows at the bumper) runs cool (that is, the metal grate feels cold compared to the right one, which ends up warm). Does the Diablo have two thermostats? Or what else could cause one radiator to run but not the other? (And could the two engine banks run with different temperatures as a result, or is all the coolant in one section in the engine)?

 

I tried to find the second coolant tank (the overflow), but couldn't. When looking at the engine from the back of the car, I only see one coolant tank on the passenger side near the firewall. I'm used to cars having a white plastic tank for the excess coolant; where should I be checking coolant levels and filling it?

 

Thanks for everyone's help. I'd like to get the temp down.

only one expansion tank on pass side. that's where you see if the level is correct. all these suggestions are good but still sounds like sticky thermastat imo.

It does sound like a fluid flow issue, I would check the T-stat like 360 suggests and then check the bleeders to make sure its burped. Does the heater blow hot air? Does the temp drop when running the heater? Try hitting the highway and cruise in top gear to see if the temp drops, more airflow help drop the temp?

It is normal if the thermostat is not opened all the way the left side radiator will run cool. Dioblo thermostats suck.. When I replace them when I had allot of them I would test the new ones. I drop 2 or 3 in 200 deg. water and see which one opens first all would be different some won't open all the way. I would pick the best ones only. I would be looking at you thermostat first as you car is running hotter then it should. You can take the old one out and test it.

Never saw a cross part number for the thermostat. Surely it's not exclusive to Lamborghini?

[in reply to previous questions by various posters]

 

1. Yes, both fans turn on
2. The temp doesn't drop noticeably when running the heater. But the heater blows some very hot air.
3. Cruising on the highway doesn't drop the temp much.

 

Interestingly enough, both radiator pipes feel quite hot when I'm done driving. If the thermostat was the problem, should I expect the return pipe to feel cool (since if the thermostat's not opening, the fluid shouldn't be flowing, right)?

 

I'll probably take the thermostat out today and boil it to check the opening. Do I just drain coolant from the base of the radiators prior to removing the thermostat, or is there some better way to make sure all the fluid gets out?

 

Thanks, everyone.

[in reply to previous questions by various posters]

 

1. Yes, both fans turn on
2. The temp doesn't drop noticeably when running the heater. But the heater blows some very hot air.
3. Cruising on the highway doesn't drop the temp much.

 

Interestingly enough, both radiator pipes feel quite hot when I'm done driving. If the thermostat was the problem, should I expect the return pipe to feel cool (since if the thermostat's not opening, the fluid shouldn't be flowing, right)?

 

I'll probably take the thermostat out today and boil it to check the opening. Do I just drain coolant from the base of the radiators prior to removing the thermostat, or is there some better way to make sure all the fluid gets out?

 

Thanks, everyone.

 

Its open some just not enough.

[in reply to previous questions by various posters]

 

1. Yes, both fans turn on
2. The temp doesn't drop noticeably when running the heater. But the heater blows some very hot air.
3. Cruising on the highway doesn't drop the temp much.

 

Interestingly enough, both radiator pipes feel quite hot when I'm done driving. If the thermostat was the problem, should I expect the return pipe to feel cool (since if the thermostat's not opening, the fluid shouldn't be flowing, right)?

 

I'll probably take the thermostat out today and boil it to check the opening. Do I just drain coolant from the base of the radiators prior to removing the thermostat, or is there some better way to make sure all the fluid gets out?

 

Thanks, everyone.

 

Even if you drain the radiators your still going to spill coolant out of the thermostat housing all over the place, so you really don't have to. You will get air in there though so you have to bleed it which is a mess too, and you might have to do it a couple of times.

Keep up the eliminatio process Fivecar, you will get it hammered out. With what you just posted it does sound like the T-stat is not opening allowing flow or the pump is not operating properly forcing flow. Keep us posted on the T-stat test.

Alrighty, everyone -- thanks to your help, this is now fixed.

 

I took out the thermostat and boiled it. Indeed, it was barely opening. So then I considered buying a new thermostat, but it would have been nearly $400. 360challenge kindly offered to sell me a 6.0 thermostat for cheaper, but in the end I drove it in to NAPA and got a new thermostat for $21.

 

NAPA Thermostat #148. Made for BMWs and other European cars. Opens at the exact temperature spec as the Diablo SV (80 Celcius). About 1/16th of an inch wider, but still plenty of clearance for the rubber gasket. Drilled my own bleeder hole. And cut my own gasket.

 

Did a test run just now -- solid 80 degrees, no more hot engine! I'll post the part number on the Parts thread as well.

 

Quick question: during the process of changing the thermostat, I lost about 5L of fluid. I filled 3L into the resevoir just now, before the test drive, but haven't bled the system. Since the temp is staying solid at 80 degrees, do I need to bleed it? What happens if I don't?

 

I appreciate everyone's help on sorting this out. Total cost of repair: $23. Cut-it-yourself gasket cost $1.50.

Alrighty, everyone -- thanks to your help, this is now fixed.

 

I took out the thermostat and boiled it. Indeed, it was barely opening. So then I considered buying a new thermostat, but it would have been nearly $400. 360challenge kindly offered to sell me a 6.0 thermostat for cheaper, but in the end I drove it in to NAPA and got a new thermostat for $21.

 

NAPA Thermostat #148. Made for BMWs and other European cars. Opens at the exact temperature spec as the Diablo SV (80 Celcius). About 1/16th of an inch wider, but still plenty of clearance for the rubber gasket. Drilled my own bleeder hole. And cut my own gasket.

 

Did a test run just now -- solid 80 degrees, no more hot engine! I'll post the part number on the Parts thread as well.

 

Quick question: during the process of changing the thermostat, I lost about 5L of fluid. I filled 3L into the resevoir just now, before the test drive, but haven't bled the system. Since the temp is staying solid at 80 degrees, do I need to bleed it? What happens if I don't?

 

I appreciate everyone's help on sorting this out. Total cost of repair: $23. Cut-it-yourself gasket cost $1.50.

 

Good deal, no overheating, no need to bleed.

 

What year is your car? I would still bleed the system and fill to the appropriate level if nothing else just to prevent corosion. Not sure which year they started but at some point they made the system self bleeding, I know mine is.

His doesn't self bleed, but the older models do, go figure.

Mine's a 98 SV. Not sure if it auto-bleeds.

 

What's the easiest way to bleed the system? The vents at the top of the radiators seem hard to reach. Would removing one of the temperature sensors above the thermostat do the trick?