Trans/engine oil service advice

[MRKS13]

Just bought 98 coupe (first Vette!!!) How do I check the transmission fluid and how do I put it in? The car has 70K on it and I don't think it was ever changed. The car is an automatic. & Is it a must to use the Mobile one synthetic oil for the engine? Can I use regular engine oil? Can I put in a 160 t-stat even though my car is all stock?

Thanks
Mark

 

[bossvette]

Don't know about the trans, but personally I would stick to Mobil 1; I have used it for over 10 years on various vehicles and it does make a difference.

Mobil 1 was the first synthetic and has the jump on the competition. I would leave the thermostat just as is also.

Welcome to CAC and Congrats on your Vette, you will have a grin on your face for quite a while

don't forget to wave to other Corvettes its an old tradition:cool

 

[warren s]

Mobil one is the factory fill and the engine oil life monitor is designed to work with it.

The 160 t-stat question is as controversial and any involving religion and politics.I run a 160 in my 99, have good results so far- But I don’t drive it in the winter months

 

[jcs712]

First, congrats on the new Vette. You could use regular motor oil but there is a reason Mobil 1 Synthetic is a factory fill. Synthetic is far superior to conventional motor oil at handling heat and friction. I read recenty that many of the C4s were equipped with engine oil coolers to keep the oil temps down. It was not until GM started using synthetic as factory fill in the C5 that allowed them to forgo the use of an engine oil cooler. My advise, stick with Synthetic.

As for your transmission, with 70K on the odometer, you should have an tech inspect the fluid. If it has never been changed, you could be in trouble. If it still looks new and does not smell like varnish, you will probably be okay to have the transmission flushed using one of the professional machines life BG. A simply drain and re-fill is not going to do it. Flusing is the way to go. NOTE - If your trans fluid is discolored or smells like varnish, leave it alone. Changing it could spell disaster for your transmission.

Just my opinion, but I would not recommend the 160 TStat. You car will burn more fuel and I doubt the horsepower gains are significant enough to feel. A TSTAT does not control max temperature as some might think. If you were to install a 160 TStat with changes to the ECM program allowing your cooling fans to come on earlier, that could yield some HP gains in conjunction with other mods. If you are talking about just doing the TStat alone, I would recommend against it. Good luck with the new car.

 

[Memf2dafizzo]

Here is how the transmission service is spelled out in the 1998 Owner's Manual, Page 7-7.

50,000 miles (80,000 km)
Change automatic transmission fluid and filter if the vehicle is mainly driven under one or more of these conditions:
- In heavy city traffic where the outside temperature regularly reaches 90 degrees F (32 degrees C) or higher.
- In hilly or mountainous terrain.
- Uses such as high performance operation.
If you do not use your vehicle under any of these conditions, change the fluid and filter at 100,000 miles (166,000 km). Manual transmission fluid doesn't require change.

If you don't know the service history of the car you should have the fluid and filter changed anyway just to be on the safe side.

As far as the thermostat change, you should reprogram the computer, w/Hypertech Power Programmer III or equivalent programmer, to accept the 160 degree thermostat so that the cooling fans will come on sooner. If not I would leave it stock.

WELCOME TO THE CLUB!!

 

[HallenTi]

I was curious myself about how to check the automatic trans fluid on my 1999 coupe, so I checked my ALLDATA information on-line. The procedure is (in it's basic form) to start and run the engine to operating temperature, raise the car, then remove the automatic transmission drain plug and check the level - it should be at the bottom of the drain plug hole. They caution to NOT turn the engine off AT ALL during this procedure, otherwise the oil will go all over. I assume that the pump is keeping the fluid at the proper level and thus the drain plug hold can be used as a guide, and if it is stopped the pump stops and all of the fluid would collect in the pan. If you are interested, I can scan the pages from ALLDATA and send them to you if you like. Tm

 

[DRTH VTR]

There is no dipstick to check the ATF level.