Oil leak detection
#1
Rennlist Member
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Does anyone have experience with finding the source of oil leaks with dye? Finished my engine rebuild and I have oil leaks near the valve covers. I have resealed them twice (the second time using pricey new valve covers. I also have a leak near the rear main (crank pulley). Unless I get better advise, I plan to try the dye technic and then pull the engine again. Yes I am a little discouraged. Any ideas?
#2
Rennlist Member
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Does anyone have experience with finding the source of oil leaks with dye? Finished my engine rebuild and I have oil leaks near the valve covers. I have resealed them twice (the second time using pricey new valve covers. I also have a leak near the rear main (crank pulley). Unless I get better advise, I plan to try the dye technic and then pull the engine again. Yes I am a little discouraged. Any ideas?
#3
Three Wheelin'
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The crankshaft nose-bearing is a notorious leak spot. Not sure if you split the case and replaced yours during the rebuild. I replaced all of the seals that I could without splitting the case, and I have a very light weep coming from there.
The rear main seal is on the flywheel side. Rear, in our case, means toward the front of the car. New seal there should be enough unless it was nicked on installation.
No suggestions for the valve covers. I used to smear some oil on the gaskets, now I rub them in molykote (dc55) so that the rubber swells and they really seal. I haven't had any leaks with either method and I always reuse the gaskets at least once. You use a 3/8" torque wrench and torque the nuts correctly?
The rear main seal is on the flywheel side. Rear, in our case, means toward the front of the car. New seal there should be enough unless it was nicked on installation.
No suggestions for the valve covers. I used to smear some oil on the gaskets, now I rub them in molykote (dc55) so that the rubber swells and they really seal. I haven't had any leaks with either method and I always reuse the gaskets at least once. You use a 3/8" torque wrench and torque the nuts correctly?
#4
RL Technical Advisor
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Dyes work very well with motor oil; one simply needs to use the correct one as its different from coolant dyes and others.
Its a well-proven method for finding stubborn and obscured leaks.
Its a well-proven method for finding stubborn and obscured leaks.
#5
Rennlist Member
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Do you have any suggestions on which type. Have a problem with a machine that is leaking and we cannot locate the leak. It is a bear to take apart due to its size. Spoke to the manufacturer and they said there is no dye that works with gear oil. Maybe motor oil is different.
#6
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Thread Starter
#7
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Thanks
The crankshaft nose-bearing is a notorious leak spot. Not sure if you split the case and replaced yours during the rebuild. I replaced all of the seals that I could without splitting the case, and I have a very light weep coming from there.
The rear main seal is on the flywheel side. Rear, in our case, means toward the front of the car. New seal there should be enough unless it was nicked on installation.
No suggestions for the valve covers. I used to smear some oil on the gaskets, now I rub them in molykote (dc55) so that the rubber swells and they really seal. I haven't had any leaks with either method and I always reuse the gaskets at least once. You use a 3/8" torque wrench and torque the nuts correctly?
The rear main seal is on the flywheel side. Rear, in our case, means toward the front of the car. New seal there should be enough unless it was nicked on installation.
No suggestions for the valve covers. I used to smear some oil on the gaskets, now I rub them in molykote (dc55) so that the rubber swells and they really seal. I haven't had any leaks with either method and I always reuse the gaskets at least once. You use a 3/8" torque wrench and torque the nuts correctly?
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#9
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Thanks for your suggestions! Based on them and another thread ("curious oil leak") I now suspect the oil line soft plugs in the cam towers may be leaking as I had them replace by my machinists.
My plan is to add the UV dye to the motor oil then run the engine long enough to circulate the dye. Then unless I can find something obvious, I will pull the engine to fully inspect.
My plan is to add the UV dye to the motor oil then run the engine long enough to circulate the dye. Then unless I can find something obvious, I will pull the engine to fully inspect.
#10
Rennlist Member
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Thanks for your suggestions! Based on them and another thread ("curious oil leak") I now suspect the oil line soft plugs in the cam towers may be leaking as I had them replace by my machinists.
My plan is to add the UV dye to the motor oil then run the engine long enough to circulate the dye. Then unless I can find something obvious, I will pull the engine to fully inspect.
My plan is to add the UV dye to the motor oil then run the engine long enough to circulate the dye. Then unless I can find something obvious, I will pull the engine to fully inspect.
#11
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I got the dye from my favorite auto supply store. Can't give you the brand. The direction state that it may remain in place and came with a engine sticker that would notify future mechanics of its presence. Since I will be removing the engine the oil will be changed.