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Hi all, new to me 2002 6x4 FD620D powered, great shape and runs well. Getting what appears to be and smells like burning oil outside the exhaust manifold seams. No smoke out exhaust pipe just seeping from seams. I believe the engine was over serviced so I removed excess oil and it did help, but still have some lingering smoke issues. Had a small issue with overtemp light but corrected that by bleeding and adding coolant. Machine runs great otherwise, it's been well cared for. Any ideas are appreciated?
 

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So is the oil at proper level now?

Sounds like valve cover gasket might be bad.

I'd clean off real good when cold, run for a while and see if you can see where the oil is seeping from.
 

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Discussion Starter #3
So is the oil at proper level now?

Sounds like valve cover gasket might be bad.

I'd clean off real good when cold, run for a while and see if you can see where the oil is seeping from.
Thank you, oil level is correct now, the engine area is very clean, but after a short (30 minute drive) I did notice some very light misting around the front valve cover. Ill clean it up and check it closely.
 

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Thank you, oil level is correct now, the engine area is very clean, but after a short (30 minute drive) I did notice some very light misting around the front valve cover. Ill clean it up and check it closely.
Cleaned around heads and valve covers, let it it run at idle for over an hour with very little smoking, so nothing telltale, ran it full out for about 5 minutes and smoke started seeping out exhaust heat shields again. Left it at idle again for 30 min, smoke stopped, stepped on throttle smoke started again. Here's a pic
13357
 

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I think you better do a leak down test or compression test.

It seems the oil would have to travel up hill if I'm interpreting your photo correctly. If this is the case it look like oil is coming out of the exhaust.

What does the oil level look like?

I'm not familiar with the type of crankcase breather this engine has, but make certain it is open. (This could be a PVC valve or other).
 

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Cleaned around heads and valve covers, let it it run at idle for over an hour with very little smoking, so nothing telltale, ran it full out for about 5 minutes and smoke started seeping out exhaust heat shields again. Left it at idle again for 30 min, smoke stopped, stepped on throttle smoke started again. Here's a pic View attachment 13357
Is the exhaust system closed with heat shields around muffler, or is it open somehow? It looks like I may have some internal holes in the exhaust pipe. None of this addresses why I have oil in the exhaust to begin with?
 

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I believe you may have engine damage or other allowing oil to get into exhaust. At cooler temperatures it condenses inside and when hot it starts to burn off.

Suggest checking.
1. Oil level (specifically is is overfilled)
2. Crankcase becoming pressurized from plugged PVC or similar system
3. Leak-down or compression test
4. Bad valve guides and/or seals

Not many ways oil can get inside the muffler and shielding.

You can always take the muffler off and look inside. If there is oil inside it is coming from internal to engine versus and external gasket leak.

Somewhere along the line you'll need to break out the wrenches and do something to investigate.
 

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Discussion Starter #8
I believe you may have engine damage or other allowing oil to get into exhaust. At cooler temperatures it condenses inside and when hot it starts to burn off.

Suggest checking.
1. Oil level (specifically is is overfilled)
2. Crankcase becoming pressurized from plugged PVC or similar system
3. Leak-down or compression test
4. Bad valve guides and/or seals

Not many ways oil can get inside the muffler and shielding.

You can always take the muffler off and look inside. If there is oil inside it is coming from internal to engine versus and external gasket leak.

Somewhere along the line you'll need to break out the wrenches and do something to investigate.
I believe you may have engine damage or other allowing oil to get into exhaust. At cooler temperatures it condenses inside and when hot it starts to burn off.

Suggest checking.
1. Oil level (specifically is is overfilled)
2. Crankcase becoming pressurized from plugged PVC or similar system
3. Leak-down or compression test
4. Bad valve guides and/or seals

Not many ways oil can get inside the muffler and shielding.

You can always take the muffler off and look inside. If there is oil inside it is coming from internal to engine versus and external gasket leak.

Somewhere along the line you'll need to break out the wrenches and do something to investigate.
That's a good checklist to move through troubleshooting, and I agree there could be mechanical damage causing the problem. Simple to complex is my plan, breather system and compression test today. Thank you, 200 mph. Will post results. What an awesome piece of equipment, nothings easy though, more fun to come.
 

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That's a good checklist to move through troubleshooting, and I agree there could be mechanical damage causing the problem. Simple to complex is my plan, breather system and compression test today. Thank you, 200 mph. Will post results. What an awesome piece of equipment, nothings easy though, more fun to come.
That's a good checklist to move through troubleshooting, and I agree there could be mechanical damage causing the problem. Simple to complex is my plan, breather system and compression test today. Thank you, 200 mph. Will post results. What an awesome piece of equipment, nothings easy though, more fun to come.
Your user name has me wondering, I fly lifeflight in Atlanta, we live at 170mph depending on the patient.
 

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Discussion Starter #10
Your user name has me wondering, I fly lifeflight in Atlanta, we live at 170mph depending on the patient.
Re verified oil level, disconnected breather tube at air intake, compression test came out 90 psi both cylinders, spark plugs look clean and dry. Everything is as advertised, no surprise. Tomorrow plan to change oil, replace both air and oil filters, then recheck everything after 5 hrs run time. I did purchase a new muffler, and a service manual. Will post when I know something new?
 

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All I learned today is my compression tester is junk, changed air, oil and fuel filter, ran it awhile to get it all warmed, recheck of compression was all over and un reliable. Machine runs great excepting the smoke from shielding on muffler. New muffler on the way, skeptical but perhaps internal corrosion? Lack of back pressure?
 

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A valid compression check would be nice. I'm thinking the compression should be much higher than 90 psi. For some reason I thought it should be around 170 psi, but I don't have a manual to verify.
 

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Discussion Starter #13
Oil level is definitely correct now. Picked up a new compression tester, new test results are front cylinder 179 psi, rear 180. Tested both twice. The leak down test is next. Thinking exhaust valves, worn guides seals, Havent seen any evidence of moisture (coolant) where it shouldn't be. Prepared for the worst , but hoping fo the best. Thank you again for your input
 

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Earlier I think you posted the oil was over filled prior to the correction. Perhaps, and this may be a real stretch here, the oil condensed in the muffler during the overfill and hasn't had enough time to burn completely off.

With 180 psi it seems like the cylinders are in good shape, but agree the valve seals and or guides could be an issue.

I'm glad the cylinders seem to be in good shape.
 

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Discussion Starter #15
Me too brother, I have much on my plate these days, hoping to use it awhile and see if the smoke calms down, will be checking the oil often for any water or trash. Thanks again! Small items left to do are; a steering rack that creaks once in awhile, starter doesn't always engage, and 1 brand new tire that needs remounting because it doesn't want to hold air.
 

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Any updates on the smoke or oil in the muffler situation? Eager to know how this turned out.
 

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Any updates on the smoke or oil in the muffler situation? Eager to know how this turned out.
The Gator has been doing great, because it was a recent purchase the previous history is unknown, but the engine oil was over serviced, and I suspect the exhaust manifold shielding had been oil soaked internally? The new exhaust and oil change( with correct level and viscosity) appears to have solved the smoking issue. It's running without issue and working daily. I named him "Dirty Johnny" pleasure to have him around.
 

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Thanks for updating and hope you don't experience the oil burning again.
 
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