Valve adjustment -- best left to mechanic?

[Murfboroman]

Hello all --

Quick question -- in the odd chance that my 1991 740 Turbo needs a valve adjustment, is that best left to a mechanic? Is that even close to being able to be done myself?

Thanks so much!

[classicswede]

All depends on tools and skill level.

Checking them is easy enough but to change the shims it is a lot less faff if you have the tools

[baggy798]

If you can do a timing belt you can do a valve adjustment! Simply remove the cam cover, undo the water pump pulley bolts and pull the pulley forwards enough to allow enough room for timing belt cover, remove distributor cap and pull out distributor assembly from end of cam, loosen cam gear bolt, set engine at TDC, loosen/push back/tighten tensioner, undo cam gear bolt and take cam gear off keeping the belt taut around it and the tensioner and just carefully balancing it on top of the water pump hose, undo cam bearing caps evenly (the bit at the back can snap off if angle is too much), remove the caps taking note of which way around they go and not to mix them up, finally remove cam to gain access to the shims!

See? So quick and easy!

Oh, you'll need a small torque wrench for the caps, 20nm, and one for the cam gear/tensioner bolts, 52nm.

Alternatively, IPD sell a compressor tool that would cut all of that out, not tried it myself though:

https://www.ipdusa.com/products/6281/Valve-Compressor-Tool-for-Volvo-IPD-114934

[Rversteeg]

Special tools

You do not need much skill, but it is hardly worthwhile doing it yourself if you have to buy the tools for it. If, like me, you are running on LPG adjusting valve clearance is more or less a routine job. It takes me less than half an hour and I am not skilled.
I would leave it to your mechanic if he has the right tools and shims in stock. Not because it is complicated, but because for the price of the tool alone you can probably have the job done.

[360beast]

If you can do a timing belt you can do a valve adjustment! Simply remove the cam cover, undo the water pump pulley bolts and pull the pulley forwards enough to allow enough room for timing belt cover, remove distributor cap and pull out distributor assembly from end of cam, loosen cam gear bolt, set engine at TDC, loosen/push back/tighten tensioner, undo cam gear bolt and take cam gear off keeping the belt taut around it and the tensioner and just carefully balancing it on top of the water pump hose, undo cam bearing caps evenly (the bit at the back can snap off if angle is too much), remove the caps taking note of which way around they go and not to mix them up, finally remove cam to gain access to the shims!

See? So quick and easy!

Oh, you'll need a small torque wrench for the caps, 20nm, and one for the cam gear/tensioner bolts, 52nm.

Alternatively, IPD sell a compressor tool that would cut all of that out, not tried it myself though:

https://www.ipdusa.com/products/6281...lvo-IPD-114934

I borrowed one of these to do mine (an eBay special version I think)

Edit: the link won't work properly but it is on Halfords website as a Laser valve shim removal tool.

https://www.halfords.com/tools/garage-equipment/garage-essentials/laser-valve-shim-remover-655030.html?cm_mmc=Google+PLA-_-Motoring%3ETools%3EGarage+Equipment%3EGarage+Essen tials-_-Motoring%3ETools%3EGarage+Equipment%3EGarage+Essen tials-_-655030&istCompanyId=b8708c57-7a02-4cf6-b2c0-dc36b54a327e&istFeedId=62b447cf-331e-4fec-a47a-9985ff72d404&istItemId=rtwriiwpx&istBid=t&_$ja=tsi d:|cid:17363835999|agid:|tid:|crid:|nw:x|rnd:14216 313111046945297|dvc:m|adp:|mt:|loc:9041124&gclid=C j0KCQiA14WdBhD8ARIsANao07iAS2kYPVMEfcpaLKewY21Idfk hVcl4xyDCfqGZkK3-XY5YCCUXGHAaAlkTEALw_wcB

Great bit of kit that saves so much hassle.

[Murfboroman]

If you can do a timing belt you can do a valve adjustment! Simply remove the cam cover, undo the water pump pulley bolts and pull the pulley forwards enough to allow enough room for timing belt cover, remove distributor cap and pull out distributor assembly from end of cam, loosen cam gear bolt, set engine at TDC, loosen/push back/tighten tensioner, undo cam gear bolt and take cam gear off keeping the belt taut around it and the tensioner and just carefully balancing it on top of the water pump hose, undo cam bearing caps evenly (the bit at the back can snap off if angle is too much), remove the caps taking note of which way around they go and not to mix them up, finally remove cam to gain access to the shims!

See? So quick and easy!

Oh, you'll need a small torque wrench for the caps, 20nm, and one for the cam gear/tensioner bolts, 52nm.

Alternatively, IPD sell a compressor tool that would cut all of that out, not tried it myself though:

https://www.ipdusa.com/products/6281...lvo-IPD-114934

Okay, so you sold me on this being complicated. I kind of got it. Now the question is -- is there a way for me to "know/tell/determine" whether the valves actually are the source of the tapping sound I'm hearing?

Main thing I'm worrying about -- I have a mechanic I trust, yes -- but what are the odds I take this thing over to him, they do what they need to do to the valves, and the tapping sound remains anyway?

Does this concern make sense?

Thanks all.

[baggy798]

Well they're not quiet engines to start with, but the valves can get louder with a bigger lash gap. The spec is 0.35-0.40mm.

Some people when doing valve adjustment put new hushers (little rubber hats that fit on the valve stem) under the buckets, this quietens the valvetrain down but not for very long - 1000 miles or so.

[Rversteeg]

Do not overcomplicate things...

I use a simplier, lever type tool as in attached picture. For getting the shims out of the bucket I use a small screw driver of which I bent the at a 90 deg angle.
Removal of the cam shaft seems quite complicated for such a simple job.

I too have some tapping nose coming from the valves, but nothing unusual. If you take off the oil filler cap with the engine running I can clearly hear that the sound is actually coming from the valves. Last time when I had the cam shaft removed the hushers were flat (no wonder after 330K miles of beating) but we did not bother about replacing them.

https://www.youtube.com/watch?v=we5Dwh9oys8

Starting at 9.00 using the lever type tool. Shims are removed with a special tool for which I use the bent screw driver instead.

[Murfboroman]

I use a simplier, lever type tool as in attached picture. For getting the shims out of the bucket I use a small screw driver of which I bent the at a 90 deg angle.
Removal of the cam shaft seems quite complicated for such a simple job.

I too have some tapping nose coming from the valves, but nothing unusual. If you take off the oil filler cap with the engine running I can clearly hear that the sound is actually coming from the valves. Last time when I had the cam shaft removed the hushers were flat (no wonder after 330K miles of beating) but we did not bother about replacing them.

https://www.youtube.com/watch?v=we5Dwh9oys8

Starting at 9.00 using the lever type tool. Shims are removed with a special tool for which I use the bent screw driver instead.

So this may sound like a "of course, you idiot" question -- but the noise wouldn't bother me as much if it wasn't coupled with a loss in performance. Noticeable. Significant. I'm assuming that when you start getting into valve clearance problems and the like, this comes with the territory, yes?

Thanks as always, all.

[Rversteeg]

When running on LPG the exhaust valve seats will slowly be eaten away, resulting in the valves closing deeper and deeper in the cylinder head. You will notice this by a continuous decrease in valve clearance. The risk of running too little valve clearance is that valves will not close properly and as they can mainly cool when they are fully during closed, will eventually get damaged due to overheating.
While running on LPG requires close monitoring of valve clearance and adjusting on some cylinders say every 20K miles, this is not the case on petrol. I have no experience with that, but can imagine that the need to re-adjust the valve clearance when running on petrol is negligable.

Obviously too large valve clearances will increase the knocking noise, while too little clearance will actually make less noise. As the valve timing takes the clearance in account as well, too large or littles clearance can have an effect on the running of the engine as well. But I am not sure when this effect gets significantly noticable.
If you doubt about your valve clearance, why not simply check them as a first step? All you need is a 10 mm spanner and a pair of feeler gauges.
A second step would be a compression test to verify if there are no burned valves.

[Murfboroman]

If you doubt about your valve clearance, why not simply check them as a first step? All you need is a 10 mm spanner and a pair of feeler gauges.
A second step would be a compression test to verify if there are no burned valves.

Perfect - right - that's some advice that is helpful. I wondered if there was a relatively quick (or at least straightforward) way to check them. That clearance can be checked fairly easily, right?

Now -- a bit more information. Definitely not as noticeable until it has warmed up a bit. Takes a few minutes.

Maybe more helpful: one of the pieces of advice I saw -- to check for piston slap -- was to unplug the fuel injector to each given cylinder and see if that made a difference. So I did that.

Cylinder 1: noise went away, car actually seemed to "smooth out" a bit; although I wonder if unplugging it causes the ECM to somehow accommodate.

Cylinder 2: again, noise went away, and it smoothed out a bit.

Cylinder 3: IMMEDIATELY DIED.

Cylinder 4: IMMEDIATELY DIED.

Remarkable the difference between the front two cylinders and the back two.

Any thoughts?

Thanks, all. I'm going to try and post some video with the noises recorded.