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Gehl 3615 3KR1 QT35 diesel

Posted: Wed May 06, 2015 3:56 pm
by Rip
My 91 Gehl 3615 was running great then it started pouring white smoke from exhaust along with oil. My first thought was a blown head gasket. Local Gehl service was not able to supply help so I am doing it. Getting into teardown found the sump filled with diesel fuel, when dipstick was removed about a quart ran over. Is this typical with a diesel? I own several diesels and this is the first to lay down. Have done all my out of warranty service for 40 years so I feel confident, but don't want to overlook anything. New gaskets just arrived from China. Any help is appreciated.

Re: Gehl 3615 3KR1 QT35 diesel

Posted: Wed May 06, 2015 7:49 pm
by Jeremy Rowland
Hi Perry and welcome to CMN :wave: I have no idea of how the engine that is in your machine is designed but here's a brief list of what to look for; Firstly if the injectors are inside the engine rocker cover check for leaking bleed off lines, then check the fuel injection pump seal has not blown and is letting diesel into the oil that way, some Cummins engines have internal fuel systems that could leak diesel into the oil and check lastly that there is no way that any external fuel oil leak has managed to get through a gasket or seal into the engine.

If you have run the engine for some hours in this condition then its a fair bet that other engine seals will have blown through excess pressure; you may also find engine bearing and cylinder bore damage because the diesel has the effect of diluting the engine oil so it cannot provide the protection for the engine that it was intended for.

Just a few pointers others on here may be able to offer you some more advice.


Re: Gehl 3615 3KR1 QT35 diesel

Posted: Wed May 06, 2015 11:20 pm
by Rip
Thanks Jeremy for the quick response. Good news is that compression looks good but dealer said it could still be a bad head gasket. Bought a complete gasket set in case it was leaking fuel from pump into sump. Engine was run less than 5 minutes total and turns over good without any issue. There was no contamination of cooling system that leaves me questioning the head gasket. Still it was far less expensive to buy gaskets and tear into than pay $145 and hour for 6 hour estimate plus parts.

Already rebuilt the drive system and hydraulic motors and lift arms. Motor is all that is left to repair.

Re: Gehl 3615 3KR1 QT35 diesel

Posted: Sun May 17, 2015 12:26 am
by Rip
Pump is wore out and I need to find a replacement. Anyone have a lead on a NP-FPR3KD55/2NP11 or old unit that I can reclaim.

Re: Gehl 3615 3KR1 QT35 diesel

Posted: Mon May 22, 2017 6:09 pm
by mechman
Any pics?