Engine rebuilt…coolant burning
#1
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Ok…..catastrophic failure …two year rebuild process..engine to Hartech in the UK for me cylinders….LN engineering, Pelican parts, vertex, Jake Rabys amazing DVD rebuild course….NOW…..engine purrs on startup…..Nice white smoke and smelly chemical air fresheners …WHAT!? Ok…first thought maybe the head rebuild was not done correctly but just did a combustion test twice …no combustion gases in the coolant..🙈…still see some white smoke out of bank 2 and somehow am burning coolant. No coolant leaks on ground …coolant system keep a neg 0.7 bar pressure for 5 minutes before I filled the coolant. Replaced the heat exchanger on the rebuild….what is happening here???? Engine light on…waiting for my new Porsche engine code reader next week …which might help.
All the posts that I have read indicate that if you have continuous whit smoke out of the drivers side exhaust (less now than 50 miles ago) that either the new head gasket is faulty(extremely unlikely), rebuilt head is faulty or the block is cracked(very unlikely)……all this but when I did the combustion test twice with the coolant reservoir ….no combustion leak identified….Relief but what now? Could The heat exchanger (new) be an issue or could I have incorrectly hooked up a line from the coolant reservoir ? Again…no coolant on the ground. Exhaust system was in dry storage for 4 years..
any helpful suggestions would be greatly appreciated.
Happy Thanksgiving to everyone!
All the posts that I have read indicate that if you have continuous whit smoke out of the drivers side exhaust (less now than 50 miles ago) that either the new head gasket is faulty(extremely unlikely), rebuilt head is faulty or the block is cracked(very unlikely)……all this but when I did the combustion test twice with the coolant reservoir ….no combustion leak identified….Relief but what now? Could The heat exchanger (new) be an issue or could I have incorrectly hooked up a line from the coolant reservoir ? Again…no coolant on the ground. Exhaust system was in dry storage for 4 years..
any helpful suggestions would be greatly appreciated.
Happy Thanksgiving to everyone!
Last edited by markus7062; 10-08-2022 at 09:09 PM.
#2
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What failed initially and how long have you run the car?
if the failure dumped a bunch of coolant or oil into the exhaust, it can take forever to burn that junk out of the system.
if the failure dumped a bunch of coolant or oil into the exhaust, it can take forever to burn that junk out of the system.
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Pressure test the system at 1.1 bar (about 16 psi). 0.7 doesn't simulate real world conditions. Get an ultrasonic sniffer and Mechanic's stethoscope to hear where the fluid is moving.
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cylinder 5 failure. Cleaned the exhaust and dried storage for 4 years. Possible that there is still exhaust residue but I was also losing some coolant and the engine light comes on….so to be cautious I stopped driving on what was only a 30 mile initial drive. Now that I have done the combustion gas test and found no combustion gases in the coolant….it might be okay to drive again to see if the problem gets worse.
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thx
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The higher pressure simulates what the system is actually seeing when being driven. At the lower pressure you tested at it may not leak. If you're losing coolant, it's going somewhere. With smoke out the exhaust, likely into the head and being burned. If you know its bank 2 when pressure testing it, remove the spark plugs and look in the plug holes with a botoscope and you may actually see coolant entering the cylinder.
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The higher pressure simulates what the system is actually seeing when being driven. At the lower pressure you tested at it may not leak. If you're losing coolant, it's going somewhere. With smoke out the exhaust, likely into the head and being burned. If you know its bank 2 when pressure testing it, remove the spark plugs and look in the plug holes with a botoscope and you may actually see coolant entering the cylinder.
thx
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#8
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Cylinders are probably intact since they're Nickies. Probably leaking in theiughbthr head to block seal so you'll still see it in the cylinders even if it's not a cracked wall. When you pull the plugs to look in the cylinders, see if one looks different than the others from being steam cleaned by the coolant burning.
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Cylinders are probably intact since they're Nickies. Probably leaking in theiughbthr head to block seal so you'll still see it in the cylinders even if it's not a cracked wall. When you pull the plugs to look in the cylinders, see if one looks different than the others from being steam cleaned by the coolant burning.
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Great news!
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Thanks for keeping us updated. Good luck moving forward.
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Another note from my side. There are leaks that are not detectable at pressure below ambient pressure and require positive pressure for detection. I have also experienced that some equipment (not with engines) leaks when warm, but does not leak when cold with overpressure (!) for testing reasons. Cooling water systems must be tested at overpressure, as this is also the working area. Porsche recommends 1barg (Workshop manual 190101). The creation of pressure below ambient pressure before filling the coolingsystem only guarantees free air of the system after filling and is not suitable for certifying tightness.
When I had a brand new cooling reservoir leaking (OEM but not genuine Porsche, lesson learnt), it took me quite a long time driving to get rid of that smell and cooling water that was on the exhaust system.
When I had a brand new cooling reservoir leaking (OEM but not genuine Porsche, lesson learnt), it took me quite a long time driving to get rid of that smell and cooling water that was on the exhaust system.
Last edited by 8x57IRS; 10-18-2022 at 04:35 AM.