Tappets, adjust, when? how?

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pandos

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I have a volvo md21b. I have never adjusted the tappets and do not know when, if ever the previous owner did it.

how would I know whether they need to be adjusted.?

Should I ignore them?, is it a serious issue?

thanks in advance.

Tony.
 
Since no one with any pretensions to expertise has answered, her's my 2p'th, strictly IMHO and at your own risk!

If you haven't done anything that would disturb them, the only change after the first year or so is wear in the camshaft, followers and rocker shaft, so they won't change much.

OTOH if you've no idea when they were last adjusted, take a feeler guage to them. Inlet 0.30mm (12 thou), exhaust 0.35 ( 14 thou), both engine warm. If they're far out - more than a few thou, they need adjusting.

Symptoms will only be noticeable if they're waaaaaaaay out - loss of power 'cos the valves aren't openong enough or poor starting due to loss of compression if they aren't closing enough. In the latter case, your valves and/or valve seats are probably knackered as well. If you haven't noticed anything wrong, it's highly unlikely you've done any damage.
 
It is something worth checking but if the unit starts and runs well don't panic. Some engines need regular re-adjustment, others don't.

I'm not familiar with that engine and have not got a w/s manual but I'm pretty sure the clearnces are quoted for a hot engine. Basically turn the engine in the normal dierction until one valve is fully open then turn it 1 revolution and adjust that valve. Repeat for all the other valves. If you are used to doing car engines you should have no problems.

If you need the w/s manual you can down load it from here

You'll probably need new cover gasket(s)
 
You need yourself a copy of the workshop manual, really you do, those old Peugeot engines the MD21 and MD32, dont think they were ever anyone’s favourite....

I tell ya the inlet valve clearance cold is 0.15mm and the exhaust valve clearance cold is 0.25mm.

It will say in the owners manual that the valves needed checking/adjusting every 100hrs or annually.
 
DO NOT IGNORE

I have done first the service of engines and found tappet clearances well out of spec, displaying poor new set up standards.

Engines will run with tappet clearances out of spec with no indication, but long term damage is highly liable.
 
[ QUOTE ]
I tell ya the inlet valve clearance cold is 0.15mm and the exhaust valve clearance cold is 0.25mm.

[/ QUOTE ] The figures Stemar quoted are not for these engines? The figures he quoted are for the MD11 etc!
 
[ QUOTE ]
I tell ya the inlet valve clearance cold is 0.15mm and the exhaust valve clearance cold is 0.25mm.

[/ QUOTE ]

Trust me, this <u>is</u> correct, not second guessed.
 
[ QUOTE ]
Trust me, this is correct, not second guessed

[/ QUOTE ] I was not implying that you were wrong rather that Stemar is quoting figures for the wrong engine.

They'll be in the w/s manual anyway and should also be in the owners manual.
 
Simple rule for basic 4 cyl engines is the "Rule of 9":

Hand turn the engine with a spanner/wrench on the crank nut, when No.1 is down, (9-1 = 8) adjust 8
When no. 2 is down (9-2 = 7) adjust 7. (down means valve depressed/open)

6 cyl engine - rule of 13 - works the same way.

Don't crank the engine over 4 (or 6) times, every little part of a turn will open one or other of the valves, all you have to do is remember when you get back to the first one. Don't force the adjustment down to trap the feeler gauge, because all you'll do is slightly open the valve and get a spurious reading. Sliding fit is good (as my wife says!!!)

Always change the valve cover gasket on refit.
 
Some Volvo engines are very critical on tappet adjustment, I know MD31 and also TMD31 as its same engine with turbo.If they are not adjusted and get too big they can cause valve failure with dire consequences.
 
[ QUOTE ]
Simple rule for basic 4 cyl engines is the "Rule of 9":

[/ QUOTE ] That applies when the valve sequence is exhaust, inlet, inlet, exhaust, exhaust, inlet inlet, exhaust but is that always the case with all push rod engines?
 
These Puegot based engines have the most weird adjusting sequence you could imagine, not suprising seeing as its French engineering.
The sequnce in the book has to be followed, the rule of 9 or doing the cylinder paired to the cyl rocking does not work with these engines, and be aware as with most french engines the No1 cylinder is the one closest to the flywhell !!
Get hold of a book as it is so complex I can't remember it to explain it.
 
[ QUOTE ]
Get hold of a book as it is so complex I can't remember it to explain it.


[/ QUOTE ] That sounds like sound advice: RTFM!
However doing the way I suggest by turning exactly 1 revolution from fully open cannot fail can it, as you will then have the camshaft turned by half a turn, even though it means a lot of engine turning.
 
Well finally got around to following the advice. Found a manual ,in Swedish, but worth following because as warned, the valves are not in normal order...
Is this record for thread resurrection...
 
pandos said:
Well finally got around to following the advice. Found a manual ,in Swedish, but worth following because as warned, the valves are not in normal order...
Is this record for thread resurrection...
Click to expand...

It is possible to buy a workshop manual in English for €16.91
 
VicS said:
It is possible to buy a workshop manual in English for €16.91
Click to expand...

Not in West Cork... And a picture saves a thousand words...I did however but 3feeler gauges having misplaced two in the last few weeks each purchased for the job...undoubtedly all three will be found tomorrow... Sods law...
 
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