S70 Engine

Post by **erikv11** » 01 Jan 2020, 12:00

I see you did a bunch of head work, did that include new valve stem seals? If not that could be another source of oil consumption. Also is a contributing factor to burnt valves.

(a) run as is adding oil
or
(b) replace the engine. Don't put in one with badly leaking valve stem seals. Also swap over all timing parts, replace cam seals, rear main seal.

Post by **E Showell** » 01 Jan 2020, 16:15

I speak Steve, that's Ph. D. for "almost."

Post by **abscate** » 01 Jan 2020, 17:39

E Showell wrote: ↑01 Jan 2020, 16:15 I speak Steve, that's Ph. D. for "almost."

corrected above

Thomas and Judith Lilli · Post by **Thomas and Judith Lilli** » 07 Jan 2020, 03:04

Yes, the head was professionally worked.

Thanks

Thomas and Judith Lilli · Post by **Thomas and Judith Lilli** » 07 Jan 2020, 03:19

Sorry Gents, once again, I’m not getting notifications on this thread.

I would not have thought about an O2 sensor causing a burnt valve but, I just replaced the exhaust system and replaced the Heated O2 with the CCV. Curious how an O2 sensor would effect one cylinder as I thought it trimmed all fuel. Interesting. I do run the highest Octane I can get on every tank full although my wife generally drove the car and, like I said we’ve had it since it’s had about 40,000 miles (2002) so what’s that about 8000 per year but I’m driving it now so it will do much more. I have noticed the consumption of oil eased a little since we replaced the exhaust. I was thinking maybe the increased back pressure from the CCV being clogged might have pushed oil out if the recovery system in the crank case.

Thomas and Judith Lilli · Post by **Thomas and Judith Lilli** » 07 Jan 2020, 03:22

Also, will a professional diagnostic machine pick up poorly functioning O2 sensors?

Post by **E Showell** » 07 Jan 2020, 05:16

Here's my theory on the O2 sensor. They degrade slowly over time. Mine did not trigger a code. One possible mode of failure is to progressively lean out the mixture (you may notice a slight increase in fuel economy). Extra strain on the engine during say a prolonged highway Hill climb generates just enough extra heat to blowtorch the valve.

Post by **Chuck W** » 07 Jan 2020, 07:17

Pick up a good-running used motor. Swap it, and be on your way.

Thomas and Judith Lilli · Post by **Thomas and Judith Lilli** » 11 Feb 2020, 12:36

An update!

Had some unrelated work done on the 90 degree gearbox. While in there, the tech changed the oil. He used Castrol GTX synthetic 5-30.
I’ve gone 1000 mile and have burned less than an eight of a court. Can’t figure it. I would have had to add a court by now.

Post by **abscate** » 11 Feb 2020, 19:40

My consumption fell on my T5 when I switched to synthetic.

The Syzygy of synthetic oil and leaks is an ongoing nuanced kerfuffle.

S70 Engine

Re: S70 Engine