My Oil Pressure Sending Unit Won't Stop Leaking.. (Page 1/1)
Threedog APR 29, 11:54 AM
Getting really sick of cheap chinese parts.

I have a 3800SC Fiero with a manual 5 speed, and I am using an 88 Fiero 2.8L oil pressure sending unit to get the readings to the gauges in the car. Problem is, they keep breaking. If I downshift too aggressively or take it to a drag strip just once(basically if the car gets near redline), the seal on the inside of the sending unit fails and it sprays oil all over the bottom/back of the engine bay. This is happening INSIDE the sensor, meaning I have to replace it. I should note that the gauge never pegs for more than a second, so its not like I have an excess of oil pressure.

This will be the 4th one I have bought off of Rockauto or from an auto parts store in the last two years. I usually change the oil and filter when I do this and I clean the bay, only to hgave it dirty and broken again in 6 months.. Additionally, the more expensive/nicer sending units on rockauto is out of stock!

Is there a better place to get them? Maybe a different sending unit to use? Should I use a lighter weight oil? I am getting sick of avoiding anything over 4k rpm because I might spray oil everywhere..
Tony Kania APR 29, 11:57 AM
That sounds as if there is another issue of over pressure in your block. Is your breather clogged? The PCV?
Threedog APR 29, 11:59 AM

quote
Originally posted by Tony Kania:

That sounds as if there is another issue of over pressure in your block. Is your breather clogged? The PCV?




I changed the PCV, and this happened with two different engines now(one a 96 N/A 3800 and one a 97 3800SC). I can try to replace the PCV again. What should the oil pressure be sitting at idle on the Fiero gauge?
Tony Kania APR 29, 12:03 PM
I have a built 3.1 with a high flow pump that makes a solid 80psi. Different from your install.

Is the PCV oily when removed? Really oily?

Edit: Look at this first. Easy to tell if it is clogged by blowing in the one way valve and either getting air passage or not.

[This message has been edited by Tony Kania (edited 04-29-2019).]

Threedog APR 29, 12:18 PM

quote
Originally posted by Tony Kania:

I have a built 3.1 with a high flow pump that makes a solid 80psi. Different from your install.

Is the PCV oily when removed? Really oily?

Edit: Look at this first. Easy to tell if it is clogged by blowing in the one way valve and either getting air passage or not.





It was back in August, I don't honestly remember. Ill check again! Thanks!
Tony Kania APR 29, 12:43 PM
Right on. Just keep an eye on it so as not to lose an engine.

Someone will chime in with better info. Good luck.
damittron APR 29, 12:56 PM
This is one reason you will find most high performance engines (ones used for racing, not just hot crusing) tend to remove the PCV valve. They will deal with a little smoke from blow-by in order to keep from blowing other parts/gaskets due to the high oil pressure filling the PCV with oil and causing a lot of pressure buildup. I personally have a old mustang with a 429 CJ, PI heads and a tunnel ram with dual 4-barrell carbs. I would never run an PCV on it.
fieroguru APR 29, 12:56 PM
PCV function has very little if anything to do with oil pressure.
The oil pressure sender on my bone stock colorado did the same thing, then the replacement lasted a week, finally got one that is still working 6 going on 6 months now.

There are certain parts I only get from Napa or GM these days...
olejoedad APR 29, 01:16 PM

quote
Originally posted by fieroguru:

PCV function has very little if anything to do with oil pressure.
The oil pressure sender on my bone stock colorado did the same thing, then the replacement lasted a week, finally got one that is still working 6 going on 6 months now.

There are certain parts I only get from Napa or GM these days...



/\/\/\ THIS /\/\/\

BUY ACDelco.
Threedog APR 29, 02:00 PM

quote
Originally posted by olejoedad:


/\/\/\ THIS /\/\/\

BUY ACDelco.



I am gonna try this one last time, then just order it through the dealer. They surprisingly have one, and its "only" $60, but I am pushing that much with each oil change and cleaning I have to do so I might just bite the bullet and buy it.

Thanks guys!