xantia 2.0 8v engine problem!

handyman · Unread post by **handyman** » 04 May 2005, 15:48

My Xantia Activa has no compression on No 1 cylinder. I have no loss of oil, no loss of water. All the other cylinders show 75 - 90 ps, as expected for the turbo engine.
Is this engine known for this problem? If yes, what is the problem, gasket, valves, camshaft, etc? I would appreciate a little guidance from those in the know before I start to strip down the head.

fastandfurryous · Unread post by **fastandfurryous** » 04 May 2005, 16:21

If it really is NO compression, then I would suspect a valve to be jammed open. If the compression is just very low, then look at a head gasket. If it is only a bit low, then possibly worn out rings. The only way to be sure is via a leakdown test, which involves piping compressed air into the cylinder via the spark plug hole. You can usually then hear the air escaping by either the exhaust, inlet system, gasket face, or breather system.
It is entirely possible to do this test yourself, by sacrificing a spark plug, welding a nut into the shell, cutting a thread on an old tyre valve, and screwing the whole lot together into the head. I've done this sucessfully a number of times in the past, and it is very revealing.

citronut · Unread post by **citronut** » 05 May 2005, 00:52

it sound like your other 3 cylenders are not very good ,compression sould read around 150psi or more,what mileage has car done,has it had a cam belt go in the past if so it might have bent very slightlybent valves regards malcolm

citronut · Unread post by **citronut** » 05 May 2005, 00:55

durr another dislecsic moment,i ment bent bent slightly slightly

fastandfurryous · Unread post by **fastandfurryous** » 05 May 2005, 01:52

As this is a turbocharged petrol engine, with a compression ratio of about 6:1 I think 90psi is about right. On a 9.5:1 Naturally aspirated engine you would expect 140psi.
Do a leakdown test, on ALL cylinders. Best to do it with the piston at TDC (obviously between compression and ignition rather than between exhaust and intake![:D])

citronut · Unread post by **citronut** » 05 May 2005, 03:36

my sons claped out ax has compresion reading around 120/130 psiand that is only a 10E

handyman · Unread post by **handyman** » 05 May 2005, 20:41

Thanks for the info, fastandfurryous. I have given the car to my local garage to take the head off to investigate, as all the possible scenarios point to an internal defect of some type. The mileometer reads 130K but I do not have any docs to prove mileage. I had at first suspected cambelt problems but up until this occured, the car was running extremely well with excellent power characteristics.
I was wondering if there was general knowledge of these engines' inherent weaknesses, like wearing rings, holing pistons, loosing valve heads, etc.
Anyway, all will be revealed shortly.

ActivaV6uk · Unread post by **ActivaV6uk** » 05 May 2005, 20:47

the C/R (compression ratio) is 8.1/1 on these. i know of some one who has a spair head and also some one who can probably suply bottom ends if you need there contact info email me.
hope your an activanet.co.uk member

Andy