Oil pressure and temperature funkiness on z34

[mrslick800]

Ok, a couple of issues with my new 91 z34. 1st, which I'm not too worried about, is the temp. This thing never friggin warms up, the only time it's gotten past the second hash mark on the gauge was when they ran it on the dyno for emissions. It ususally hovers around the first mark, is that normal? I have the fans on a switch (the last owner did that so he could cool the motor between runs at the track.

The other thing is the oil pressure. I'm not sure if it's just the gauge or what, but when I first drove the car home from Mass where i bought it, 180 miles, the thing ran around 50 pounds under cruise, 2-3 grand and never more than 60 or seventy above that. Then a few days later all of a sudden the gauge jumped to 80 pounds, and pretty much stayed there. Now its 80 poundsat idle unti lit warms up, then its about 70, sometimes it ill drop to 40 or 50 at idle, but as soon as I take off its back to 80 or so. Needless to say when I mash it the needle's pegged. Could this be a bad gauge or sending unit? I have heard excessive oil pressure is bad for this motor? I am really loving this car and don't want it to die on me.

also, how do i check the codes on the ecu?

[pocket-rocket]

For the cooling issue, start small, change your t-stat, it might be stuck open. For the oil pressure, is there a Fram on there? My 91 used to do the same exact thing yours is doing until I put a Purolator on there in place of the Fram. Frams are bad news.

[mrslick800]

actually there is, good tip, I guess I'll be changing that soon.

also, your signature is hilarious

[pocket-rocket]

Thanks, I robbed it from a friend that I play Final Fantasy XI with, lol. Reason they read so high with the Fram is they have flow problems. On the DOHC, GM put the oil pressure sensor in between the pump and the filter. Now what happens to the pressure when you restrict flow? It goes up (assuming your oil pump is good, lol). Ben turned me on to Purolators. I used Frams because I saw thats what my grandfather has trusted over many years. I passed the news on to him and explained how I had evidence since then. Advance now markets a new filter made for them by Purolator, called Total Grip (so you get the grippy stuff like Fram, but all the way up the can), from what I was told by the store manager down the street. He's been in the car industry something like 30 years, so I trust what he says.

Prices for my zip code are as follows:


Purolator Oil Filter-Premium Plus
PN:L24011
$3.18

Fram Oil Filter-Extra Guard(R)
PN:PH3980
$3.77 (cheapest Fram I saw listed for our Z34s)

Advance Auto Parts-Totalgrip Protection Plus Oil Filter
PN:AA3980
$2.88

If you haven't noticed, I like Advance. Not to bash Autozone, I've just had way to many bad/defective parts from Autozone since doing my own work, and I just got set up on a commercial account at Advance a few days ago, lol.

[mrslick800]

I tend to prefer advance myself, for mostly the same reasons, around there their people tend to be a little sharper too. I chose the Fram because of the super fine filtration on them, its a whole bunch of microns finer than most of the ones in that price range. I was thinking about trying one of those freer flowing filters with that magnet thing they have that attaches to the outside of the filter to help with the filtration, I hear they work really well.

[pocket-rocket]

I chose the Fram because of the super fine filtration on them, its a whole bunch of microns finer than most of the ones in that price range.

I agree, microns are good, but in this case I think the old saying "Too much of a good thing is bad" holds oil.Magnets are good, if not, they wouldn't make oil pan drain plugs with them, or put them in tranny pans. One time, my master cylinder was going out in my car. Only one of my front tires was stopping the car because as W body owners we all know how awesome the rear brakes are. Anyways, I went into Autozone and asked the guy behind the counter about it, even though I had a feeling about it being the master cylinder. I was OK with doing brake jobs, starters, alts., and changing fluids at the time, and not much more. The dude said that he thought I had a sticking caliper..... I asked if he was sure, because it sounded more like a master cylinder to me. He said yeah, caliper. So I left, went down the street to Advance and the guy there confirmed my suspicion, and said master cylinder as we laughed at the Autozone guy.

Later after getting a lot more comfy with cars, I decided to work at Advanced after the manager offered me a job delivering parts because he saw me in there all the time. I went in for the interview, and the other manager was the one who interviewed me. He asked me to name all of the fuel system components starting at the gas tank and ending at the engine. I grinned, looked at him and asked "carbed or fuel injected?" We got a good laugh out of it, and they hired me. But yeah, they always seemed a bit more keen to cars at Advance then they do at Autozone. Like I said, too many defective parts at Autozone (2 clutches, 9 alternators all in the same car...). Oh, and Firefox underlines Autozone every time I spell it, but not Advance, so Firefox must not like Autozone either :P

[latemodelnewbee]

if you change your own oil you over qualified to work at autozone.

[pocket-rocket]

if you change your own oil you over qualified to work at autozone.

ROFL! Thanks man, I needed a good laugh today. I feel like crap and am sore all over from burning the midnight oil tearing a clutch out of a 95 Jetta. All I can say about Jettas is the clutch set up on them is freaking weird. For one, it has no throw out bearing. Two, the cable hooks to the side of the tranny, not the bellhousing. The "flywheel" bolts to the pressure plate which is bolted to the crank. Yes, I typed that right, the pressure plate is bolted to the crank. I had to take a cover off that was retained by a huge C clip that pushes on the pressure plate fingers when a rod that comes out of the center of the input shaft pushes on it from you pushing the clutch. This thing was so worn out, there were no groves in the material, and it went as far as to start wearing the springs down from metal to metal contact on the clutch disc. Freaking weird man... I'll be taking pics of that one for sure. The "flywheel" almost looks like a brake drum except instead of the service area being on the inside race like surface like a drum, its on the back portion that would be contacting the hub. Strangest thing I've ever seen TBH. But at least my friend only paid $150 for it.

[mrslick800]

good news. today I switched from my fram oil filter and 10w30 quaker state Q to a mobil 0ne oil filter and 5w30. the car now usually runs around 60 pounds, and doesnt even touch 80psi until 6 grand or so, which considering the temp (still running cool, havent checked thermostat yet) seems about right. Seems to have solved that problem. No more fram filters for the TDC.

[pocket-rocket]

Glad that took care of it for you I almost was to the point where I was going to change my sensor when mine started doing that. That would have been disappointing to find out it wouldn't have fixed it, lol.