Strange coolant leak. Any suggestions? - LotusTalk

lotusdriver2001 · 11-01-2009, 01:33 PM

The car is a 2003 - V8. There is a cooling leak and the coolant seems to be coming out the bottom of the bell housing. The way I found this is by putting a hand-powered pressure bleeder on the header tank in place of the overflow tank hose. I pressurize the system to about 10 -12 lbs (based on the car having a 15 lb. cap) and coolant drips out at the bottom of the bell housing.

Are there freeze plugs in the back of the engine? Is there a pathway for coolant to get in there from the top?

Any ideas?

Simba · 11-01-2009, 06:07 PM

Check the turbo coolant lines along the top of the transmission.

There's also an aluminum crossover pipe in the same area, could have developed a crack, or a cracked hose.

lotusdriver2001 · 11-01-2009, 08:34 PM

Thanks but I did check the turbo lines, and just about any other lines I could see, find, and reach. Did discover that when the shop did my timing belt they appear to have removed the hoses for the coolant pipes in the front of the engine, both of them, for access. They were loose and leaking. I had to reach up there and tighten them. Just a benefit of chasing this problem.

The coolant appears to be coming from inside the bell housing. I'm wondering if maybe there is a freeze plug under the fly wheel that could be leaking.

Perhaps a head gasket leaking into the center of the engine and running down somehow inside the bell housing?

I'm really sort of hoping of something easy that I'm missing. Neither of the two options I mention are exceptionally pleasant.

Seb · 11-01-2009, 08:45 PM

There should be no freeze plug on the transmission side of the engine from what I'm aware of. I would start from the top of the engine and work down. Gravity is a great tool to diagnose fluid leaks.

Simba · 11-02-2009, 06:44 AM

There's no freeze plug, but the thermostat housing is on the top of the engine under the intake manifold, it's possible they didn't seal that properly and it's pooling and leaking out through the rear of the engine.

The only other possibility in that area would indeed be a head gasket, however were it leaking badly enough for you to notice it dripping, you'd be pegging the temp gauge and crop dusting the neighborhood with white smoke.

I'd say pull the trunk floor out, start it up, and watch. When the system pressurizes you'll see anything that amounts to drips of coolant.

billt · 11-03-2009, 06:08 AM

Assuming fluid is coming from the bell housing weep hole you can plug it then release after runing to see if this is true. I believe it's a small leak from elsewhere as only tranny grease or engine oil would come from the weep hole. It must be a very small leak or your "add coolant" light would have come on by now. If you've checked all the lines then look closely at the water pump.

jtrealty · Yesterday, 07:28 PM

The thermostat is on the front of the motor on the V-8, not near the bell housing. The thing to do is to remove the trunk floor and pressurize the cooling system. There are hoses coming off of the back of the motor that go to the turbos and there is a header bottle which could be leaking. Worst case is a head gasket. It is possible there is a leak on top of the motor and it is running down the back over the bell housing. Not likely it is inside the bell housing. The low coolant light may not be working. The float on the sensor gets stuck if the header bottle is dirty. The header bottle is supposed to be filled to the top and the overflow bottle in the R/R wheel arch is supposed to fluctuate. The hose from the header bottle to the overflow bottle can get plugged up.
David Teitelbaum

11-01-2009, 01:33 PM	#1 (permalink)
lotusdriver2001 Registered User Join Date: Mar 2004 Location: Manteca, CA Posts: 71	Strange coolant leak. Any suggestions? The car is a 2003 - V8. There is a cooling leak and the coolant seems to be coming out the bottom of the bell housing. The way I found this is by putting a hand-powered pressure bleeder on the header tank in place of the overflow tank hose. I pressurize the system to about 10 -12 lbs (based on the car having a 15 lb. cap) and coolant drips out at the bottom of the bell housing. Are there freeze plugs in the back of the engine? Is there a pathway for coolant to get in there from the top? Any ideas?

11-01-2009, 06:07 PM	#2 (permalink)
Simba 2/3 hp to the paws. Join Date: Jan 2008 Location: NY Posts: 497	Check the turbo coolant lines along the top of the transmission. There's also an aluminum crossover pipe in the same area, could have developed a crack, or a cracked hose. Last edited by Simba : 11-01-2009 at 06:13 PM.

11-01-2009, 08:34 PM	#3 (permalink)
lotusdriver2001 Registered User Join Date: Mar 2004 Location: Manteca, CA Posts: 71	Did that one... Thanks but I did check the turbo lines, and just about any other lines I could see, find, and reach. Did discover that when the shop did my timing belt they appear to have removed the hoses for the coolant pipes in the front of the engine, both of them, for access. They were loose and leaking. I had to reach up there and tighten them. Just a benefit of chasing this problem. The coolant appears to be coming from inside the bell housing. I'm wondering if maybe there is a freeze plug under the fly wheel that could be leaking. Perhaps a head gasket leaking into the center of the engine and running down somehow inside the bell housing? I'm really sort of hoping of something easy that I'm missing. Neither of the two options I mention are exceptionally pleasant.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

11-01-2009, 08:45 PM	#4 (permalink)
Seb <3 QR25DE Join Date: Mar 2007 Location: Austin, TX Posts: 753	There should be no freeze plug on the transmission side of the engine from what I'm aware of. I would start from the top of the engine and work down. Gravity is a great tool to diagnose fluid leaks.

11-02-2009, 06:44 AM	#5 (permalink)
Simba 2/3 hp to the paws. Join Date: Jan 2008 Location: NY Posts: 497	There's no freeze plug, but the thermostat housing is on the top of the engine under the intake manifold, it's possible they didn't seal that properly and it's pooling and leaking out through the rear of the engine. The only other possibility in that area would indeed be a head gasket, however were it leaking badly enough for you to notice it dripping, you'd be pegging the temp gauge and crop dusting the neighborhood with white smoke. I'd say pull the trunk floor out, start it up, and watch. When the system pressurizes you'll see anything that amounts to drips of coolant.

11-03-2009, 06:08 AM	#6 (permalink)
billt Registered User Join Date: Apr 2009 Posts: 15	Assuming fluid is coming from the bell housing weep hole you can plug it then release after runing to see if this is true. I believe it's a small leak from elsewhere as only tranny grease or engine oil would come from the weep hole. It must be a very small leak or your "add coolant" light would have come on by now. If you've checked all the lines then look closely at the water pump.

Yesterday, 07:28 PM	#7 (permalink)
jtrealty Registered User Join Date: Nov 2009 Posts: 3	The thermostat is on the front of the motor on the V-8, not near the bell housing. The thing to do is to remove the trunk floor and pressurize the cooling system. There are hoses coming off of the back of the motor that go to the turbos and there is a header bottle which could be leaking. Worst case is a head gasket. It is possible there is a leak on top of the motor and it is running down the back over the bell housing. Not likely it is inside the bell housing. The low coolant light may not be working. The float on the sensor gets stuck if the header bottle is dirty. The header bottle is supposed to be filled to the top and the overflow bottle in the R/R wheel arch is supposed to fluctuate. The hose from the header bottle to the overflow bottle can get plugged up. David Teitelbaum

Currently Active Users Viewing This Thread: 3 (2 members and 1 guests)
carbuff, Gixxer