compression and leak down test to start
scorred cylinder walls could kill performance
So can I rule out scoring in any of the cylinders since the car still pulls like a train? Literally don’t notice any performance issues
Now i feel like something is just WAITING to go wrong.
I’d say its a good sign but its tough to say unless you drive multiple 4.2 S4s all at the same time, its decieving trust me. If you want to run some logs it may help diagnose, feel free to pm me.
Lubro Moly used to be a full synthetic and was pretty good stuff. I ran it for a while and a lot of enthusiasts recommended it so JHM offered it on their site to meet demand. As of last year, JHM apparently ran it in all their cars (but I think they run the 5W-40).
However, it’s not the same formula that it used to be, and is no longer a “full” synthetic. I’ve gone to Motul Xcess 5w-40 (which JHM now also carries) and have been very happy with it as it is a full synthetic and some of the best stuff you can reasonably get out there.
Really can’t rule out cylinder scoring until you do a compression test. “Pulls like a train” is pretty relative to your butt dyno, i.e. very inaccurate.
If you can pull the coil packs you can do a compression test. It’s actually very easy, I did one last night since I was changing my spark plugs and relieved to see everything come back good.
Thanks guys. Last thing I wanna do is sell her. Heading in to my guy now for a compression test, hoping to at least rule out cylinder scoring here. What would a leakdown show me??
valve seals
For my own education, what are you looking for in the logs (003/020/021 presumably) to suggest cylinder scoring/decreased compression?
I had oil consumption and it was the valve cover gaskets.
I can qualify how well it pulls based on acceleration rate compared to mods/weather and a few factors in the logs
Valve cover gaskets were replaced about 35k ago. I know it is a common issue on the 4.2’s but I just can’t see as to how just the valve cover gaskets would leak THIS much oil.
Just left the car with my buddy/mechanic to drive and test. I know I am getting a bit ahead of myself here, but what happens when the compression test and leakdown test both come back ok? I doubt they will, but would that eliminate some MAJOR possibilities?
Totally agreed that my feel for the cars speed may be scewed as it is the only 4.2 i EVER drive. The only real reason that I say “it pulls like a train” is because I race my dad in his 2009 Challenger SRT-8 all the time and I am consistently a half car behind him to 80 or so. Has been this way for 3 years.
If compression and leakdown come back ok I would look at the PCV system and front and rear main seals
Exactly, jack up the car and check the under pan for any oil leaks on the top of it. Also check under the transmission for oil residue. Other thing you can do is park your car for a day or two over very clean ground which will help identify any dripping.
Car sat in the garage for 4.5 months over the winter and not a spot of oil on the ground. I feel like, with the volume of oil i burn/lose, I would have noticed a major leak by now as the underpan has been pulled quite a few times. Where are the front and rear seals located? Are they easily visible or is it a big job to get to them? If for some odd reason that turns out to be the case is it an expensive fix? Motor drop?
Thanks again guys. Lots of great info here
my car burned oil too, and you could eat off the garage or my bellypan. It also pulled hard, running 12.9 with a modest modlist of tune downpipes/catback/lwcp/lwfr/instake spacers.
It raced RS4s, B8 S4s, new Mustangs, B5 S4s…and never let me down. Could be valve seals. Could be a dozen things.
After the car is parked for a few hours, set up your video camera (point and shoot, phone, whatever) justbehind the car so that it can film the exhaust pipes when it starts up. I’ll bet you a case of Coke you have blue smoke at startup.
Saki-
What would blue smoke illustrate? (rookie question i know)
Ill first start with the leakdown and compression and see where that takes us. I will have to weigh repair costs vs just selling her depending on if we can even diagnose the problem.
The car rarely lets me down as you stated. I love watching peoples faces after they think Im in a shitty A4
Blue smoke means burning oil I believe?!!
In most cases:
Blue smoke = Oil
Black smoke = Fuel
White smoke = Coolant (smells sweet, not the condensation you get in the mornings.)
Car is there now. Prob won’t be tested til monday or so but I will get back with the compression and leakdown results. I would really like to at least find out what EXACTLY the problem is before I decide to fix/sell for money purposes and for my own personal curiosity.
Saki, You may have to run through the “dozen other things it could be” depending on these results!
Not a dozen. If you aren’t leaking it, it’s obviously being burned. valve seals, pcv, scored walls. I have never heard of another way for it to be consumed/burnt