jasoncway

I just became the proud owner of a 1998 Camaro Z28 that rolled over 140000 miles on my trip back to Louisiana fron Dallas, TX where I picked it up. I have NO experience with the these besides they used to wax my butt in a drag race in my younger days. My concerns are with temperatures and oil pressure. Oil pressure runs 40 cold and 25-35 hot. It was about 92 degrees today coming home. Oil pressure would run about 25-30 at 75-80 mph on the interstate that was about 2400 rpms. At an idle oil pressure would drop to 20-25. I don't know what weight oil is being used in it. I just got it and have not had a chance to change it yet. The temperature would run about 180-185 cruising, but would climb to 210 when at a red light in traffic. I was not running the a/c. It is a convertible so I had the top down. I know I may need to investigate a little, but if this is normal behavior I don't want to be chasing problems that aren't problems.
Any and all help is appreciated.
P.S. this car is a one owner all stock car with only a Flowmaster and a K&N added.

Thanks, Jason

Andrew1989

iTrader: (4)

Maybe the oil has just broken down a little. Throw some new oil in there and see how the pressure is after that. It has happened to me before. Also don't be surprised when your ar burns a quart of oil every 3000 miles or so.

98ZEMT

iTrader: (5)

Well, to put your mind at ease, I also have a 98 Z with 104k miles on it. I've owned since 91k. Idle oil pressure has always been 20 when warmed up. Cruising pressure is around 35-40. I would still change the oil to a quality synthetic. As far as the temp goes, mine stays at 170. But thats because I have a tune and a 160 t-stat. When it was stockish, I would have about the same temps you describe here. Check the between the ac condensor and radiator. You'll probably find all sorts of leaves and crap there. Clean that out and it will probably get better.

Finkledbody

That seems very low for oil pressure in these engines.

jasoncway

Thanks for the information. I was considering using Amsoil 5W20. Would this be a good weight oil or would I need to use a little heavier weight oil to get the pressure up a little?

lt1formula275

my 02 ws6 has 79000 miles 40psi at idle at 210 degrees, bout 45-55 at 2000rpm. my temp stays at 210 degrees while cruising. and ever so slowly creeps higher if your at a stop for a really long time. also ive only had the car bout 2 months. and its bout due for another oil change and the oil pressure is not as high now as it was 2000 miles ago. so your oil could be broken down some.

BOONEY7750

99 with less than 30K, temp is ALWAYS 210, oil preasure is NEVER lower than 40psi (according to the stock gauge) and will increase with RPM's about 5psi for every 1,200 RPM. Change the oil and filter. I use mobil 1 10w30. I would use Amsoil 10w30 if it was widely available close by. I would then consider seeing if your gauge is even accurate, or drop your pan and see if it is clean and oil can flow easily.

98RedBird

iTrader: (77)

Alright. 210 is normal for the temp. That's what they are programmed/designed to run at. Some guys put a colder thermostat in and program the fans to kick on earlier.

The oil pressure is low. 98's are notorious for iffy oiling systems. My 98 did the same thing that yours is doing. I swapped pumps out in it and it held 40 psi at hot idle. Granted you do have a higher mileage situation so you will lose a little oil pressure due to your clearances opening up a little. Try a oil change and filter change and if nothing changes then I would look at changing the oil pressure sending unit and then possibly swapping out pumps. It's a fairly inexpensive piece to swap out and not too mechanically involved. Oiling is something you don't want to mess around with. If you're going to be beating on the car or modding the car at all get your oil pressure right first.

blackz28x07

The pressure at idle seems fine, mine idles at ~23 psi at a hot idle, the thing that concerns me is the pressure when cruising 75-80. You should at least be 40 if not higher with those rpms. If I were you I'd get a ported ls6 pump just to be safe.

Paint_It_Black

iTrader: (1)

In 99+ models the temp gauge is a dummy gauge, it always reads 210 as long as it's within a certain range.

chadaclysm

Add me to the 210 and 40+ list. The only time my oil pressure goes below 40 is on hot days at full operating temp at idle, and id say then its never below 35. I've never ever seen the temp gauge go over 210 (knock on wood).

RPM WS6

iTrader: (3)

I agree.

You mentioned 92° outside temps, which is very hot. I would expect slightly lower than normal OP readings at that temp. Mine would be somewhere between 25-30psi after extended idling in 90°+ outside temps, but my motor has significantly less miles. Also, keep in mind that the '98-'00 LS1s use a different oil pump from the '01+ cars, so you can expect any '98-'00 to have lower oil pressure at the same rpms compared to a '01+.

Having said all that, your pressure at 75-80mph does seem pretty low. First thing I'd do is change the oil and see what happens. I like Mobil 1 0w40 for these engines. If pressure is still too low, I would look at swapping out the oil pressure sending unit next; this can often be the cause of low readings. If all else fails, you could upgrade to an LS6 oil pump, but depending on why the pressure is low, this may or may not help you. If internal engine wear is the reason, then all the oil pumps in the world won't correct that condition.

jasoncway

I ordered some amsoil 10w30 yesterday and I am going to change the oil and filter. I have to put a power steering pump on which I have read is not uncommon on these cars too. I was going to try all the oil pressure fixes leading up the oil pump replacement and if I end up needing an oil pump I can do it without the p/s pump in the way. I was still old school and thought the oil pump was inside the oil pan. Shows you how long it has been since I had a hot rod...Now I just have to keep my wifes foot out of it so I can get the money for tires....She is rough on tires now that she found out how much fun this thing is to drive.

blackz28x07

Well good luck, hopefully it's a cheap/easy fix.

NeedaV8foundation

iTrader: (4)

id also try using an additive in your oil, either slick 50 or i really like the lucas oil products. My dad works in the truck industry and was telling me about the new findings that they have when using oil additives (yes i know this is different from cars but still) but there is truth behind oil additives, you just gotta make sure your not putting too much in and make sure your using the right additive for the application.

jasoncway

OK. I found another problem????maybe. Drivers side valve cover at the rear there is a round housing with a hose attatched to it that heads to the passenger side around the back of the intake manifold. While feeling around for the oil pressure sensor I found this hose to be broken right in the middle behind the intake manifold. It was dirty and oily like it had been that way for some time. Is this some of the crankcase ventilation? I lost where it went once it came out from behind the intake on the passenger side. Once again any and all help is appreciated.

98ZEMT

iTrader: (5)

That was your wonderful PCV system hose. I hate those damn things. When I bought my car, mine was toast. The whole damn hose assembly fell apart. So, I made another one using fuel hose and a brass T. Works. Replacement from GM is like 150.

jasoncway

Sounds like I'll be going to get a brass T and some fuel hose.

chi-town hustler

X2, even idling wit a/c it neva goes pass 210 deg. 40+.
Conv 02 z28, 127k, no mod.

jasoncway

I finally got the oil changed and that did the trick. Oil pressure came up to 50psi at idle when cold. Running 35psi at 210 degrees at idle. Hit the throttle and oil pressure goes as high as 60psi. Runs around 50psi when cruising...I feel much more comfortable with these numbers. I guess that oil was broken down and in bad need of a change.
Thanks to all who gave me the much needed advice.