Shop put new head on, Wierd oil pressure readings

Snotcycle

New Member
Jul 16, 2006
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Palo Alto, CA
So last week i was getting BHG symptoms real bad, (couldn't just add coolant and limp to a station, had to get a tow) so i take it to my shop and find out the head is warped, the gasket was fine...go figure.
Well now supposedly thats fixed and the car was given an oil change while it was in there. Picked it up yesterday, the oil pressure gauge is WHACK... at first i was getting negative oil pressure, then only like 2-5psi, then after a bit of driving around it SHOT UP, i mean the needle actually jumped straight to 80+psi.

Ok...wierd enough, after some more driving the oil readings level out into the normal 20-45psi. got drunk at a friend's last night and stayed there, this morn i come to start the car up and it skips the low pressure stage and jumps right up to the 80-120psi range, drove it all the way home like that, never moved more than a few PSI in either direction.

Yesterday when it was reading low, before it started getting really psycho, i called the shop foreman and told him of the issue, he said to drive it like that (guess he'll be paying for the rod knock...) for a week and if it doesn't stabilize to bring it back in.

Just a note: I trust this mechanic, not with my life, but i stop by and chat with him pretty frequently and i've seen 2-3 other mk3's that come in and out of there, and a single turbo mk4 with nitrous that gets its work done there.
 

Snotcycle

New Member
Jul 16, 2006
128
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Palo Alto, CA
jetjock said:
Negative pressure? Not possible. Must be an instrument error. Check the sending unit and wiring.
will do after the sun goes down and its a bit cooler, i asked mechanic if he touched the sender, said no
HellsLegion said:
Was it working correctly before the swap?
yes, was reading 20-45psi all day every day, sometimes a bit above that when i was running the car hard
 

Snotcycle

New Member
Jul 16, 2006
128
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0
Palo Alto, CA
so i looked at my car where the TSRM shows the oil sender to be... and the car's way too hot to actually get in there and start playing/looking around, this'll have to wait til tomorrow. If anyone has any other suggestions as to what it could be, please drop me a line.

Thanks in advance!