Do I have worn valves?

[89berlina]

Hey guys,

Have a 1989 VN berlina wagon and its sounding quite sick at the moment. Has abit of a "chug-a... chug-a" (best way to put it in words) sound at idle which Ive began to notice. Car had been running alot quieter and smoother but now its abit rough at idle and can be hard to start at times. Was wondering if it may be worn valves? If it is, how big of a job is it?

Thanks in advance

[black as]

Do a compression test that should give you some idea of what state your motor is in, are you burning any oil because if you think your valves are worn so would the valve stem oil seals, hence burning oil

[Pub247]

You need to do a compression test check all cylinders a few times each. If you have some that are low on comp put some oil into the bore and try again, If the comp goes up its more than likely your rings if comp stays the same then its likely to be valve related. Thats probaly the easiest way to tell without ripping your head off. Do you get much crankcase fumes?? its also another indication of worn rings

[89berlina]

Yeah, might see if I can take it down to the mechanic down the road who said he'd look at the car for free. Not burning any oil at all and there's not even a hint of black smoke from the exhaust.

[Pub247]

Do a compression test that should give you some idea of what state your motor is in, are you burning any oil because if you think your valves are worn so would the valve stem oil seals, hence burning oil

Not totally correct burning oil on cold starts that goes away when warm is an indicator of stem seals or worn guides. Stem seals arent a big problem on v6's as compared to v8's or holden 6cyls as they're are much better design

[Pub247]

Yeah, might see if I can take it down to the mechanic down the road who said he'd look at the car for free. Not burning any oil at all and there's not even a hint of black smoke from the exhaust.

Black smoke would be petrol blueish smoke is oil but if theres no smoke then thats good. Is the car on gas??

[centy]

look for an exhaust leak aroung the manifolds to and cracked passenger side manifold if series 2.
compression test
look for leaking head gasket
check crank case pressure
if 1 pot is low put a little heavy oil or grease in that pot and run for a few seconds the test again (if fixs the low compression then worn rings)

If it is a stuffed head then a replacement engine is probably cheaper.
gasket set
and either
replacement heads or head shaving.

[89berlina]

Hey guys,

Havent replied to this post in ages! My apologies. Checked compression on all cylinders and all read above 1200 kpa, which is way above specs Its both a good and a bad thing. Good - because I dont need a new engine. Bad - because I still dont know the problem Well anyway ordered a new fuel regulator because I have my suspicions it may be the problem. Tested it the other night, when the car was idling. Whenever I removed the vacuum hose from the regulator and put it back on, the car almost stalled. Not sure if this means anything but I will know by tomorrow when I get the new regulator

[jetspin_vn]

F A U L T C O D E S!!! Have you checked them??

[89berlina]

Yeah, I always check the fault codes and it this time it said everything is operationing normally. Anyway found the issue. Changed fuel regulator but it didnt make a difference. What I did find is that my fuel filter was backed up with rusty coloured gunk.

So planning to change the filter, but before I do, discconnect the old filter and bleed some fuel out of the tank into a jerry can to hopefully get rid of the remaning gunk in the tank before I put a new filter on.

Thanks for the help guys

[jetspin_vn]

Sweet, always good to find the issue. You might want to consider giving the tank a proper clean up, and pull the pumps off for a clean as well.