valve clearances- does it need to be done?

If it really does run perfect Brian then there isn't any need to do anything , but it doesn't work that way.

What should happen is that they should be checked and adjusted only if required.

You won't know if valves don't quite open far enough normally.

Its not to hard to check them with feeler guage.
Checked my 4800 petrol patrol few weeks ago at 120,000 and 1 or 2 are almost at needing adjustment.

Saves a lot of cost just doing the check and no adjustement your self

Robin Miller

I was quoted $150 to do the shims on the hilux not including the costs (if any) if it needs shims. Was told up to $250 worst case senario. Apparantly they can swap and change them around to a certain extent. I have no idea if the cruiser is the same set up as my lux but may require special tools to remove and replace the shims. With out the special tool is a pain in the ar@e job, what I have been told. I have asked the same question before and simple answer is yes if you dont want to be burning valves out. I havnt had myn done now for 120k was going in to get done same time as turbo but canned that so havnt had done. Am getting done in 2weeks time unless I sell it first in which case I will inform the new owner they need doing. Myn is the same no problems no smoke etc but need doing all the same. Just my opinion, maybe the cruiser is totally different. Regards Steve M

Brian

Found with my 80 s 1HZ that it needed a couple of fairly major adjustments, at 100 & 200k approx. Since then it has settled and does not seem to be moving any more - they checked but did not adjust at 300.

The adjustments made a huge difference in power, especially the first. Other mechanics have told me it necessary to check till it settles.

Max

As an ex-disel mechanic, I can tell you that it is vital that you get 'em checked and if required, adjusted.

It's a long winded job on any engine and a lot more so on a 6 cylinder diesel. It's also a job that you can get wrong very easily - with catastrophic results on a diesel. Bent con rods, burnt vales, holed pistons, bent camshafts (OHC), bent pushrods (OHV) just to name a few,,,,,,,,,

I know of one very infamous one that I myself stuffed up when I was young and in a hurry and took a chance on it,,,,,,,,,Cost a heap of dough that one did.

If you're not skilled in this area, then get someone that is skilled to do it - and make sure it is actually done. Try making little tell tale marks around the rocker cover gasket joint ( a bit of paint etc) etc, check out what needs to be removed to get the rocker cover off and take a picture of it. Check it later to see if it actually has been removed etc.

A good wipe of the rocker cover with an oily rag can make it look like the job's been done,,,,,,,,,,,,,to an inexperienced eye.

Bottom line - GET IT DONE.

Bilbo

Hi Brian.

I have read some of the well meaning replies to your question and came to the conclusion that they weren't written by mechanics.

The main reason for checking valve clearances is to ensure that AT LEAST ENOUGH clearance exists.

With increasing mileage and age, valve stems stretch due to spring pressure and heat. Also valve seat reccession and valve train wear causes the valve to clearance to decrease

If the valve clearance is too tight they "ride", ie: don't close properly as the lobe of the camshaft holds them slightly open on the firing stroke.

This causes the exhaust valve seats to burn due to hot gasses escaping past the valve.

I would get them checked and adjusted if required as it is a lot cheaper than removing the cylinder head for a valve grind.

Eddy

Essential part of maintaining any vehicle - diesel, petrol or LPG.

Dont risk it.....Its worth spending a little now rather than spending thousands later. As said above....its an essential part of servicing any vehicle.

Having said that, ide better get mine done too (80 Series, 1HZ)
Cheers
NUTS!

Valve clearances shuold be checked every 40,000k's (according to gregorys manual) for 1HZ