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| White smoke from exhaust | Rate Topic |
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| Posted: 07-08-2025 12:33 am |
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1st Post |
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JH16196 Member
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Greetings All, My wife's JH recently developed a lot of white smoke from the exhaust. Prior to this the car ran fine with only a trace of greyish smoke on acceleration. It happened immediately after starting a flooded engine. I thought it would clear up do to the flooded engine but the white smoke persists and gets worse as the car is driven. I understand white smoke from the exhaust is caused by coolant entering the cylinders and could be due to a blown head gasket or even cracked cylinder. So I did a few test to see if I could determine the cause. 1. Compression test good with all cylinders 175-180 lbs. Th ought this might show any issue with a blown head gasket. 2. Leak Down Test. All cylinders except #3 20% or under. But #3 around 50% leakage and bubbles appearing in the radiator. So this now looks like a blown head gasket. I was thinking it might also be a blown intake manifold gasket but no air leakage around this manifold. So wondering what others think about the diagnosis or other possibilities. Very strange if it is the head gasket why it would fail when trying to start a car with a flooded engine. Also, the head was rebuilt by Delta a few years ago due to bad exhaust valves. When I installed the head I used a composite gasket with original head studs torqued to 81-85lbs per recommendation of Delta. However, I understand from reviewing some posts on this forum there is some controversy over torque values using composite head gaskets with factory studs. Could improper torque values used when I installed the composite head gasket caused the issue? The car has only been driven about 2500 miles since the head was re-installed. Any comments and recommendations are greatly appreciate. Thanks, Brit
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| Posted: 07-08-2025 01:38 pm |
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2nd Post |
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noomg Member
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Brit, I'm not sure what you mean by "starting a flooded engine". Are you talking about getting too much gas during start up? If that's the case the motor usually won't start until enough gas gas has evaporated so it really won't start in a flooded condition but afterwards. With a manual choke and electric fuel pump the J/H is really hard to flood but even so I don't see how it could effect the head gasket, it could just be a coincidence. Is the white stuff coming from the tailpipe smoke or steam? Steam indicates water smoke of course oil. A compression test will usually identify a blown head gasket and bubbles in the radiator can also be an indicator. Since your compression is good I wouldn't be in a big hurry to pull the head I'd try a couple of things first. I'd retorque the head to make sure it's tight then if there's no difference I'd try some stop leak. Oh, one more thing has the coolant level been going down?
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| Posted: 07-08-2025 04:26 pm |
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3rd Post |
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JH16196 Member
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noomg Thanks for your response. Flooding the engine was due to to much choke and pumping the gas to start. We waited until the gas evaporated and then got the engine to fire. But that is when the white smoke developed which was never their before. Coolant level was down so it is seeping into cylinder #3. I will try re-torquing the head to see if that helps. Not sure I want to introduce something like stop leak into the coolant system. The coolant system does maintain its pressure when the car runs. Brit
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| Posted: 07-08-2025 05:57 pm |
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4th Post |
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noomg Member
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Brit, I realize some guys a reluctant to introduce stop leak into their cooling system and I get that but I take a more practical approach, if it's a choice between replacing the head gasket or adding a bottle of Bar's Stop Leak it's a pretty easy choice for me, you'll have to make your own choice. If it doesn't work you'll have to pull the head and flush it anyway and the addition of stop leak to the cooling system may help you pinpoint where the problem is.
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