A question about coolant and overflow

[rjd2]

Hi all-I'm fairly new to the Delorean game; acquired my '83 earlier this year. I have a question:

As I try to periodically check all the fluids on my cars, I checked the coolant reservoir about a month ago, and it looked almost empty. I could see the bottom of it. So I filled it up about halfway. This week, I changed the oil, and I noticed coolant dripping off the drivers side of the underside of the transmission housing after running the engine for 5 minutes to loosen any engine gunk. When I checked the coolant reservoir, it was still about half full. It didnt seem to dissipate by much after my last filling.

Does this sound normal? If not, what's the best way to check for leaks around the water pump? Thanks for the help! -RJ

[DMCMW Dave]

Hi all-I'm fairly new to the Delorean game; acquired my '83 earlier this year. I have a question:

As I try to periodically check all the fluids on my cars, I checked the coolant reservoir about a month ago, and it looked almost empty. I could see the bottom of it. So I filled it up about halfway. This week, I changed the oil, and I noticed coolant dripping off the drivers side of the underside of the transmission housing after running the engine for 5 minutes to loosen any engine gunk. When I checked the coolant reservoir, it was still about half full. It didnt seem to dissipate by much after my last filling.

Does this sound normal? If not, what's the best way to check for leaks around the water pump? Thanks for the help! -RJ

No leaks are normal. It's common since the car has so many leak points - lots of hoses. The best way to find the leak is with a cooling system pressure tester, you may be able to rent one from Autozone.

The driver side of the underside of the transmission isn't anywhere near the water pump. It's more likely one of the hose joints or the fan temp switch (otterstat).

[David T]

No leaks are normal. It's common since the car has so many leak points - lots of hoses. The best way to find the leak is with a cooling system pressure tester, you may be able to rent one from Autozone.

The driver side of the underside of the transmission isn't anywhere near the water pump. It's more likely one of the hose joints or the fan temp switch (otterstat).

If you notice the header tank that empty you have to worry that you may have air in the system and just filling the header tank is not enough. You should open the bleeder screw on the thermostat housing and make sure there is no air in the system. As for leaks, it may be time to replace a lot of hoses and clamps. Because there are so many connections, and each one has the potential to leak, it is often better to just replace everything rather than chasing after them one at a time. Leaks in that area could be from some of the connections in the front of the motor for the heater, the heater valve, etc.

[rjd2]

thanks folks! i'll do some investigation on this info!

[DaraSue]

Have you recently installed an off-brand thermostat, by any chance?

(Ok that probably wouldn't cause the leak to appear near the transmission, but it sure wouldn't help...)

(To go a little more in depth here, I had a Napa thermostat put in on the road and 700 miles later, my car was leaking coolant from a couple different places I'd tighten one clamp, something else would leak, then it started spraying from the thermostat housing and it was, as far as we've been able to determine, due to a bad gasket in the new thermostat. Sometimes individual leaks are only part of the story.)

[David T]

Have you recently installed an off-brand thermostat, by any chance?

(Ok that probably wouldn't cause the leak to appear near the transmission, but it sure wouldn't help...)

(To go a little more in depth here, I had a Napa thermostat put in on the road and 700 miles later, my car was leaking coolant from a couple different places I'd tighten one clamp, something else would leak, then it started spraying from the thermostat housing and it was, as far as we've been able to determine, due to a bad gasket in the new thermostat. Sometimes individual leaks are only part of the story.)

You didn't have a "bad" gasket, it was most likely a WRONG gasket. The surfaces are machined such that you must use a special gasket that the thermostat fits into. It is a square kind of "O" ring with a slit on the inner diameter that allows the gasket to fit around the thermostat and seal both sides and the thermostat at the same time and the housing. Doubtful you will find it anywhere but a Delorean vendor in the US. The other problem is many "replacement" thermostats will not have the "jiggle pin" that allows proper air bleeding. As for the leaks, you probably have old hoses and till you replace them all you will be chasing leaks one-at-a-time as they fail.

[DaraSue]

You didn't have a "bad" gasket, it was most likely a WRONG gasket. The surfaces are machined such that you must use a special gasket that the thermostat fits into. It is a square kind of "O" ring with a slit on the inner diameter that allows the gasket to fit around the thermostat and seal both sides and the thermostat at the same time and the housing. Doubtful you will find it anywhere but a Delorean vendor in the US. The other problem is many "replacement" thermostats will not have the "jiggle pin" that allows proper air bleeding. As for the leaks, you probably have old hoses and till you replace them all you will be chasing leaks one-at-a-time as they fail.

That's what I meant, sorry for not being more specific. My mechanic said the NAPA thermostat actually did have the jiggle pin, but it sounds like it came with a flat o-ring instead of the C-shaped one that the DMC one comes with. The seller said he thought he'd replaced the thermostat too so the right one might not have even been in there for comparison.

The hoses on mine had been replaced by the seller, although from the looks of it he used aftermarket ones, since one of them didn't quite fit right (since replaced). My mechanic recommended switching the worm clamps for T-clamps so unless anybody has a reason why what's a bad idea, I'm going to have that done, too, and OP may want to consider it.

[David T]

At Rob Grady's tech session this past weekend he was showing off some of his new products. One was a kit of all silicone hoses with the correct hose clamps. You may want to consider them. If you don't have the correct gasket seal for the thermostat you should remove the thermostat and replace the seal with a correct one.

[DaraSue]

At Rob Grady's tech session this past weekend he was showing off some of his new products. One was a kit of all silicone hoses with the correct hose clamps. You may want to consider them. If you don't have the correct gasket seal for the thermostat you should remove the thermostat and replace the seal with a correct one.

Yeah, they're doing that now. I got the DMC one but hadn't put it in yet (I let my mechanic talk me out of it because he said the Napa one had the jiggle pin but I'd forgotten about the O-ring). Thanks for the tip about the hoses, I'll look into that.