oil leak help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

mnz28 · 04-22-2007, 08:19 PM

Hey people,
Im having major problems with my 87 full size blazer 4x4. I have a nice steady drip of oil coming down near the filter area. I thought at first a fitting for the oil cooler was loose. I looked into it somemore and got oil dripped all over me. Above the filter on the block I have a roughly 3/8th inch pipe thats about 3 inches long with a 90 deg fitting on the end. Threaded into it is a sensor of some sort with a wire coming out of it. If I pop the hood it is directly behind the ds exhaust manifold. Well anyway the oil appears to be coming out of this sender. I dont think this has anything to do with the oil pressure gauge as the sender for that is behind the throttle body. What is this "sender" ? Can I just plug it off and be good to go?

screwballl · 04-26-2007, 11:41 PM

now the question is... is it a big block of small block? Big blocks have their oil sending unit/gauge hookup there. If it is a small block or V6 then its located by the distributor (and not what it would be for you).
likely just the sending unit seal needs replaced

Damien · 05-08-2007, 11:35 AM

The leaky sender should be the sender for your gauge in the dash. The sender behind the TB is for your fuel pump. The oil leak is coming through the diphram in the sender. Replace the sender.

mnz28 · 05-09-2007, 06:01 AM

It was the sender, rusty and weak. Is it possable Gm put 2 senders in and just hooked one up depending on if you have a gauge or dummy light?

Damien · 05-10-2007, 12:51 AM

I am assuming your truck is fuel injected beacause you mentioned a throttle body. The one but the distributor is a fuel pump cut off. If you don't have enough oil presure the fuel pump shuts off, hopefully saving your engine. The sender on the side of the block is for the gauge in the dash. hope this helps.

KShortell · 05-21-2007, 09:35 PM

Also check to make sure that it's not leaking from the factory oil cooler adapter. I had that problem a couple of years ago. There's a $3 gasket that goes between the adapter housing and the block.

In regards, to the sensor you see down there, some years had the gauge pressure sender. It looks like a large bell-type sender.

Good luck!

04-22-2007, 08:19 PM	#1
mnz28 Registered User Join Date: Jun 2006 Location: wi Posts: 16	oil leak help Hey people, Im having major problems with my 87 full size blazer 4x4. I have a nice steady drip of oil coming down near the filter area. I thought at first a fitting for the oil cooler was loose. I looked into it somemore and got oil dripped all over me. Above the filter on the block I have a roughly 3/8th inch pipe thats about 3 inches long with a 90 deg fitting on the end. Threaded into it is a sensor of some sort with a wire coming out of it. If I pop the hood it is directly behind the ds exhaust manifold. Well anyway the oil appears to be coming out of this sender. I dont think this has anything to do with the oil pressure gauge as the sender for that is behind the throttle body. What is this "sender" ? Can I just plug it off and be good to go?

04-26-2007, 11:41 PM	#2
screwballl Tonawanda 454 Join Date: Mar 2004 Location: Liquid Sunshine State Posts: 2,754	Re: oil leak help now the question is... is it a big block of small block? Big blocks have their oil sending unit/gauge hookup there. If it is a small block or V6 then its located by the distributor (and not what it would be for you). likely just the sending unit seal needs replaced __________________ 91 Chevy Suburban Tonawanda 454 R2500 - SOLD!!! 04 Dodge Durango 5.7L Hemi 2WD, 24K miles (as of July 2011) In the past 30 years about 90% of Fords are still on the road, the other 10% made it home. -------------------

05-08-2007, 11:35 AM	#3
Damien Registered User Join Date: Mar 2007 Location: Farmington, MN Posts: 928	Re: oil leak help The leaky sender should be the sender for your gauge in the dash. The sender behind the TB is for your fuel pump. The oil leak is coming through the diphram in the sender. Replace the sender. __________________ I can still count my vehicles on two... wait three hands.

05-09-2007, 06:01 AM	#4
mnz28 Registered User Join Date: Jun 2006 Location: wi Posts: 16	Re: oil leak help It was the sender, rusty and weak. Is it possable Gm put 2 senders in and just hooked one up depending on if you have a gauge or dummy light?

05-10-2007, 12:51 AM	#5
Damien Registered User Join Date: Mar 2007 Location: Farmington, MN Posts: 928	Re: oil leak help I am assuming your truck is fuel injected beacause you mentioned a throttle body. The one but the distributor is a fuel pump cut off. If you don't have enough oil presure the fuel pump shuts off, hopefully saving your engine. The sender on the side of the block is for the gauge in the dash. hope this helps. __________________ I can still count my vehicles on two... wait three hands.

05-21-2007, 09:35 PM	#6
KShortell Registered User Join Date: Oct 2003 Location: Chesapeake, VA Posts: 734	Re: oil leak help Also check to make sure that it's not leaking from the factory oil cooler adapter. I had that problem a couple of years ago. There's a $3 gasket that goes between the adapter housing and the block. In regards, to the sensor you see down there, some years had the gauge pressure sender. It looks like a large bell-type sender. Good luck! __________________ Semper Paratus Last edited by KShortell; 05-21-2007 at 09:37 PM.

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