Oil Leak Into Cab

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

YakkoWarner

Full Access Member
Joined
May 29, 2024
Posts
165
Reaction score
192
Location
Central Texas
First Name
Wolf
Truck Year
1989
Truck Model
R2500 Suburban
Engine Size
454
You just reminded me of something that I always wondered about... and you answered my question too! So maybe 20 years ago, Chrysler put out an updated oil pressure sender pigtail for a lot of their mid and late 90's cars. They had problematic and leaky oil senders. But anyway, the updated pigtail had a tiny little hose coming out of the connector. I always wondered "how the hell is that supposed to improve anything"? I thought it was really dumb.

But now I know why! That hose vented the leaking oil and kept it from pushing up the strands of the wire and ruining it. Of course, I guess it still didn't matter much because those cars were terrible with underhood wiring anyway, lol.

I had a 1992 Escort (essentially a rebadged Mazda) that had the speedo cable wicking oil into the panel and down onto my leg problem once. Never seen anything like that before.

And of course anything British just leaks oil as a matter of principle. My current 1970 British project drips oil on the shop floor (4 to 6 drops a week apparently) despite not having actual been run in well over a decade and the engine being dry for that time (its the transmission thats leaking and replacing the gasket likely to be the issue would involve splitting the entire transmission casing, for 6 drops a week I'll live with it for now).

My parking space under my Suburban used to look like a crime scene from transmission fluid until I replaced the vacuum modulator, now it just looks like a bad circular saw accidedent happened under there.
 

Scribbles

Full Access Member
Joined
Feb 2, 2012
Posts
53
Reaction score
61
Location
az
First Name
Mike
Truck Year
89
Truck Model
2500
Engine Size
350
Hello everyone, I’ve got an 1986 GMC K1500 with an oil leak going into my cab under the dash right in the center. Yes! It is oil not coolant or tranny fluid. Does anyone or has anyone ever come across this issue? I have no idea how this happened and I have never heard of this before. Thank you for your time
I had this problem in my van and it was a blown head gasket. The oil flowed into the heater core and blew a hole in it then leaked into the cab.
Probably shouldn't trail an overloaded trailer filled with music equipment and 5 sweaty dudes up into the Rocky Mountains to play a concert at a skate park, just because.
 

cornholeeo

Junior Member
Joined
Feb 27, 2024
Posts
5
Reaction score
3
Location
usa
First Name
corn
Truck Year
1977
Truck Model
c20
Engine Size
454
Every 671 I've worked on leaks, if it didn't you may be out of oil.
good point, i was going to suggest to drain the oil and run the engine to see if the leak was still there, instead of crawling under the dash. JK
 

JBswth

Full Access Member
Joined
Jan 24, 2022
Posts
225
Reaction score
182
Location
Vallejo, California
First Name
James
Truck Year
1973
Truck Model
C25
Engine Size
292 cubic inches
Every 671 I've worked on leaks, if it didn't you may be out of oil.
That's what they used to say about Harleys - if it doesn't leak, it is out of oil.

J. B.
 

kenny68chevy

Junior Member
Joined
Aug 30, 2024
Posts
2
Reaction score
14
Location
mt airy md
First Name
kenny
Truck Year
1968
Truck Model
c10
Engine Size
454
If you have an electrical oil pressure gauge and it is leaking oil inside your truck under the dash, your oil pressure sending unit is bad . The electrical current will pull oil through the wire all the way to your oil pressure gauge. I have seen this only a few times and I have been a mechanic for 45 years .
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,446
Reaction score
8,679
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
If you have an electrical oil pressure gauge and it is leaking oil inside your truck under the dash, your oil pressure sending unit is bad . The electrical current will pull oil through the wire all the way to your oil pressure gauge. I have seen this only a few times and I have been a mechanic for 45 years .
Covered back in post 8 and 9. Yep, it's not common,but it happens. I fully believe that the oil is pushed, by the oil pressure and uses the wire as a hose. The cars with spade connectors, when the sender goes bad the oil just drips at the sender. Its the ones with molded rubber boots that push oil into the interior. Nonetheless it does happen. It happens with coolant senders too. Looks like you're new around here. Welcome!
 
Last edited:
  • Like
Reactions: WFO

Latest posts

Forum statistics

Threads
44,157
Posts
950,593
Members
36,272
Latest member
armchair
Top