Alecw81 »
Ive got a 98 S70 GLT with 242k miles. This weekend I replaced the PCV system, plugs and wires.
What other “high-milage” maintenance should I be planning?
I’d like to seafoam the engine, and possibly switch to silicone vacuum lines, radiator hoses, and turbo hoses. However, I’m worried about the seafoam doing more harm than good, and the silicone possibly not being worth the investment on a car with nearl 250k miles.
I had the timing belt/water pump done approximately 60k miles ago.
As far as I know, it’s still got the original turbo and exhaust.
- serpentine belt tuneup
- front driveshafts
- power steering flush
- transmission flush
- replacing the oil pan O-rings
- compression test
- pre-emptive fuel pump replacement
Glencoeteen »
how smooth does the motor sound? My 98T5 is just shy of 211k 
and it runs like a motor with 50k it does need the PCV done, I did seafoam treatment through the vacuum tree in small amounts let it sit for 15 mins and then ran it and it smoked like crazy, but my results are idled smoother and boy did it get better gas millage.
+1 on the drain and fill, my transmission is the original and works just like it did when new, every other oil change it gets 4qts drained and then refilled, cost is the same as an oil change and the reward is 211k on one transmission and looks like it will go another 211k. and this is in Miles.
jimmy57 »
I think the silicone hoses would be overkill. I doubt you’ll go another 13 years unless you decide to be the second Irv Gordon (2.6 Million miles on a 66 P1800).
I wouldn’t do any internal engine cleaner either. You have 242K miles you have been doing something right. That something is you probably drive a good distance to/from work and the car doesn’t see long warm-ups followed by short trips to create sludge and add unnecessary engine hours.
I do disagree with steam cleaning or pressure washing engine though. The age of that car almost assures that some of the seals in connectors and covering on wires is compromised. You may open a can of smelly worms doing anything that can force water into those items. Engine cleaner and a garden hose with sprayer is pretty safe but you’ll still probably have to remove cover and blow out spark plug wells.
I would make sure the serpentine belt idler and tensioner pulleys are good as that could lead to a thrown belt into timing belt and end the long run in an instant.
Front driveshafts are worth a good check.
Maybe a power steering flush is a good idea.
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Last Updated on June 3, 2025
