C5 Service Advice

My lovely C5 is now coimng up to 1 year old, and I have completed just under 3k miles in that time, the odometer is reading approx 57K miles at the moment.

The oil, fluids etc all look in perfect condition, but as it will be at the local garage for it's MOT in a couple of weeks time, I thought I may as well get it serviced as well?

So a few questions What would a recommended service be at that mileage? Engine oil change only or should I get the brake and power steering fluid done too? Also when does the auto transmission fluid need changing usually, and are ther any other things to check at this time? Finally there any special parts or fluids I would need to get ordered from the states in advance?

Many thanks,

Philip.

It is not just how many miles the car has, but how old the oil and fluids are
Could be other than the engine oil, all else is what GM put in when built

If you intend to keep the C5 for a long time I'd suggest changing it all, brake, power steering, tranny rear end and coolant flushed
at least then in the future you'd know the state of them

Interesting story,
I was doing with my custom 1999 C5 a 120-mile Open Road Race, speeds at times over 220 MPH in Nevada summer where weather was over 90 F degrees
Has a 3.73 rear end gear instead of the stock 3.42 so that meant engine RPMs were higher putting more load and heat into everything

About 60 miles into the race I noticed out the hatch window while smoke pouring out but all the dash gauges showed no issues
As you know once in a race mindset you never want to give up so I said hell with it and I would keep race speed until something blows up
Smoke never stopped for the 40 miles to finish line
2 time Indy 500 winner Roger Ward who hosted these races laughed and told me later he thinks I killed every bug in 2 counties

Point is the stock GM tranny fluid could not handle the heat and expanded enough to blow out the vent hole on top of the tranny
and that fluid than sprayed onto both hot exhaust pipes and burned off

So depending on how you drive the C5, the stock fluid is not good enough
Being since the C4 GM has not only used Mobil I for oil but also for their own racing used their tranny and rear end fluids

Select the Mobil 1 "Synthetic" versions for engine, tranny and rear end as its maintain better in hot temps and not degrade

If you do not race than stock like DOT 3 or 4 brake fluid is fine also stock power steering fluid

Flush, replace the fluid and filter for the tranny
Flush coolant and use GM Dexcool anti-freeze at 50/50% with water

If you download an owners handbook, it will tell you what needs servicing and when and what fluids to use. Here's an example:

Thanks for the replies @teamzr1 and @Rich and also thank you for the link to the owners manual. What you are saying makes sense and I will get the garage to do a full fluids service.

PS interesting story JR - I guess you must have had some very serious mods to get over 220 MPH in a C5 - that is astonishing! My Corvette leads a much more sedate life, so I doubt any risk of boiling my transmission fluid!

Philip.

I usually have the oil and filter done by my local garage at MOT time every year, supplying them with the correct oil/filter. As above if you're not sure when everything else was done, worth getting it done now to set a baseline.

Thanks @C5Steve - which filter and oil do you use?

Mobil 1 (5w30) and an AC Delco pf46e filter. Keith at Eurovettes has both in stock in the UK (the Mobil 1 is the one with a specific addictive I can't remember which one it is off the top of my head).

On subject of engine oil and tranny fluids
I assume in the UK you have testlabs like we do in the USA where you send them a sample of engine oil and tranny fluid
and they test them, write the test results for you and also keep those results on file so later samples you send them can be compared
This shows the signs of internal wearing, if leaks like coolant or exhaust seen in the oil and what metals are wearing too soon
and also testing of tranny fluid went to the test lab
Costs, is like $35 per sample
Results report shows what metals or fluids seen, and the values should be to compare to your test results

This allows to make repairs sooner before more internal damage

Also, good to have that history to show buyers if you're selling the vehicle

Here you see results of my 1999 and the tests done over years from 2001 to 2022
This is useful as I inject water/methanol and 200 HP shot of NOS into intake manifold

phn said:

Thanks @C5Steve - which filter and oil do you use?

Click to expand...

Best filters tested in the USA comes from WIX, have used them for many years

teamzr1 said:

On subject of engine oil and tranny fluids
I assume in the UK you have testlabs like we do in the USA where you send them a sample of engine oil and tranny fluid
and they test them, write the test results for you and also keep those results on file so later samples you send them can be compared
This shows the signs of internal wearing, if leaks like coolant or exhaust seen in the oil and what metals are wearing too soon
and also testing of tranny fluid went to the test lab
Costs, is like $35 per sample
Results report shows what metals or fluids seen, and the values should be to compare to your test results

This allows to make repairs sooner before more internal damage

Also, good to have that history to show buyers if you're selling the vehicle

Here you see results of my 1999 and the tests done over years from 2001 to 2022
This is useful as I inject water/methanol and 200 HP shot of NOS into intake manifold

View attachment 29134

Click to expand...

We do, but they're not as common not inexpensive as over there. Its pretty unheard of for anyone to go to that extreme in terms of history, although it is very interesting. Unless you're buying something with a seriously built engine that's been used for Motorsport perhaps

C5Steve said:

Mobil 1 (5w30) and an AC Delco pf46e filter. Keith at Eurovettes has both in stock in the UK (the Mobil 1 is the one with a specific addictive I can't remember which one it is off the top of my head).

Click to expand...

Thanks! I have ordred the Mobil 1 ESP oil and also I ended up buying a AC Delco GOLD UPF46R filter. I also bought a new air filter as well and will be getting the brake fluid changed out.

phn said:

Thanks! I have ordred the Mobil 1 ESP oil and also I ended up buying a AC Delco GOLD UPF46R filter. I also bought a new air filter as well and will be getting the brake fluid changed out.

Click to expand...

Sounds like you've got all the bases covered!