Symptoms of Diesel Valve Mis-Adjustment

Quick question:

What are the symptoms of diesel intake/exhaust valve misadjustment?

Are you refering to too much lash or not enough as both will present differing symptoms.

Please state the symptoms of each separately?

Assuming that the OP is asking about increased clearances caused by normal wear the first symptoms will be increased tappet noise. Other things will follow if the clearances are allowed to get greater.

If the misadjustment is caused by incompetent assembly on the other hand - the sky is the limit.

Pro-Nav2.7TDi said:

Please state the symptoms of each separately?

Click to expand...

what symptoms are you experiencing?

Adjusted the lash to workshop manual specs, no massive noticeable difference even though they were out of spec to begin with.

Engine: TD27 4cyl NA diesel

Symptoms - I'm chasing out a rough idle - idle is supposed to be 750 +/- 50 RPM, idle incredibly rough at 750, currently set to 1000+RPM and still shakes the whole vehicle.

Next thing to eliminate is injectors.

Pro-Nav2.7TDi said:

Adjusted the lash to workshop manual specs, no massive noticeable difference even though they were out of spec to begin with.

Engine: TD27 4cyl NA diesel

Symptoms - I'm chasing out a rough idle - idle is supposed to be 750 +/- 50 RPM, idle incredibly rough at 750, currently set to 1000+RPM and still shakes the whole vehicle.

Next thing to eliminate is injectors.

Click to expand...

Have fun finding this one

Could be from a lot of things.



If it did happen to be valve related,

(although from only your short description i tend to say no),

but anyway,
a burnt valve,
a non closing valve either from a foriegn object lodged on the valve seat,
or from a sticking or bent stem,
or from incorrect lash adjustment(valve not permitted to close),
or a weak or broken valve spring,
would cause a rough idle depending how bad the opening was
and which valve was affected,
but the biggest symptom you would notice was lack of power, especially trying to power up a hill,
and some serious backfiring when driving.

Try a comp test first off the go from there.

Happy trails...............

Well not long to go until you get the new powerplant.

Will catch up with you when your down.

Dave.

Krankin said:

a burnt valve,
a non closing valve either from a foriegn object lodged on the valve seat,
or from a sticking or bent stem,
or from incorrect lash adjustment(valve not permitted to close),
or a weak or broken valve spring,
would cause a rough idle depending how bad the opening was
and which valve was affected,
but the biggest symptom you would notice was lack of power, especially trying to power up a hill,
and some serious backfiring when driving.

Try a comp test first off the go from there.

Click to expand...

Thanks Krankin

I don't get any backfiring, above 1500RPM it's smooth. I'll keep eliminating options.

Yeah Dave I know but this has annoyed me since I bought it, plus I'm deciding what to do with the TD27 and if I sell it want to be able to sell it as a smooth working motor.

Anyway, see you there