Hilux 4x4 Forum

So I have noticed for a few months now, when I start the bakkie(22r) in the morning I get what sounds like a bottom end knock, like there is no oil pressure.It takes only 2 to 4 seconds to go away completely. What got me worried now is the fact that if i start the vehicle hot it will make the same noise. I know that some say that a knock knock on start up is normal.

Bump

Hmmm...... What's the mileage on the motor? What you describe sounds a lot like worn hydraulic lifters but the 22R is an OHC motor, so it can't be that.

It does nonetheless sound like an oil pressure related thing and I'm wondering what it could be - if the crank or big end bearings are so worn that they start up noisy, then the chances are that they will remain noisy, hot or cold. I'm wondering if it's not perhaps the rocker shaft.

A stethoscope is probably going to be of little help to locate the origin because you wont have enough time before it quietens down - unless you are two, one starts and the other listens and even then it may take a few noisy start-ups to pin point.

Maybe someone else has a better idea.

I think the incorrect spec engine oil can also cause a knock when the engine is cold. If the oil is to thin you will have excessive clearances on the main and big end journals. This can cause a knock until the crank heats up and expands.

Just my 2CW


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I am using Fuchs Titan truck plus 15w 40

No, I'm sure that the crank would take a lot more than 4 or 5 secs to warm up and close tolerances. It really sounds like an oil pressure related issue and the oil viscosity will certainly be part of it.

Did this start happening after a service or oil change?

Man, I don't know why I didn't think of it before ...... TIMING CHAIN TENSIONER & GUIDE!

It's an hydraulic tensioner, so it's dependant on oil pressure. So that makes sense to me now. However I don't think that the hydraulic tensioner itself is the main problem - I think that's still working OK because as it takes up the tension, the noise disappears. However, you should replace it as part of attending to the main problem, and that is that the timing chain guide is probably collapsed - and that's where the noise is coming from.

This is something that you should attend to ASAP because if the guide disintegrates altogether the chain will rub up against the housing and there's a water jacket right there at the water pump. If it chews it's way through there then you have much bigger problems.

You should replace the chain, tensioner (it will also be worn) and guide all at the same time - usually available as a complete kit. You can replace these parts without having to take off the cylinder head but to get that front cover off you have to strip away everything in front of the timing chain cover and it's not difficult, just tedious. Might as well take the radiator out as well for some extra space to work and flush that at the same time.

To get the chain cover off there's the obvious bolts facing the front of the motor but there is one that's hidden inside the top of the head. You will have to remove the tappet cover anyway and once it's off you will see the hidden bolt in a hollow at the front of the head. Once you have it all exposed, check that you have the motor positioned on TDC with compression stroke on #1 cylinder (the timing mark on the cam sprocket will line up with the mark on the head). Use the split-link in the chain to remove it and put the new one on in the same way - the timing marks on the crank and cam must line up when the chain is taut on the chain guide side.

If you have any doubt about DIY on this job, it's not rocket science and I recall that "CasKru" did a write up with pics when he did his some time back (do a search).

I am almost 100% certain that this is the cause of your problem. Good luck.

One more thing .... use OEM parts ..... not worth taking a chance when it's such a tedious job and the pirate tensioners have a tendancy to 'stick'.

The pieces that have broken off from the guide will be lying at the bottom of the sump. You might want to drain the sump and see if you can fish out any bits that you can see after the front cover is off, or you can drop the sump and clean it out properly. If you choose to leave the bits in there, the chances are very good that they will remain at the bottom of the sump without causing any problems, but it's not a guarantee.

Luke I see yours has 375k on it - even though there is no telling how long these chains last it would be impressive if the rattle only started now on an original chain... other member's views on this?

What I'm getting at is it is feasible to thread a new chain through the top of the motor without dismantling the whole front IF the guides etc are in reasonable condition. I'm not sure how many mechanics do this but I rate if your chain was replaced at some time by Toyota according to their manual they would have done the procedure as outlined by Andy and hopefully replaced the guides & tensioner as well in which case you would stand a good chance of just having to thread through. It is of course the better option to do the complete procedure but if the quicker option prolongs the need for it by another 100k km's without damaging the motor later on then consider it.

Scope out Cassie's post so you know what you're looking at then pop off the tappet cover and check down there with light and a small extended mirror and see how the guides look, if they're cracked, broken or severely worn. You may be able to shift the chain and check the tensioner wear although that is far down. Don't drop anything! Tie the garage utensils to a string or something. If you have service history see if you can find record of the chain being replaced.

Hoppy recently threaded a new chain through into mine with 250k on the original chain, fortunately the guides seemed good, and although there was no apparent knock/rattle beforehand it is quite evident that the motor does sound very smooth and quiet afterwards. By the way the OE Toyota chain does not have a split link (or at least my original and OE new ones didn't) - you get this from Masterparts, cut a link out of the new chain and the old chain still in the motor, link the new to old, turn the motor to pull the new chain through and connect it up. If you stuff it you're in trouble, rather get Hoppy to do it;) R375 for Toyota chain, R7 for link and labour. 1 hour instead of two days:) IF your guides aint shot.

Yes, the chains do stretch a bit over time (not like the old double link ones that hardly stretched at all), and the tensioner is supposed to take up that extra slack. But here's the thing, when that happens the tensioner surface becomes worn to the new sharper curvature of the chain running over it - now fit a new chain and leave the old tensioner and the chain runs on a smaller surface (apex of the old wear pattern) - result is that it wears down relatively quick and you have to replace the tensioner anyway.

The chain guide surface tends to wear quicker than the tensioner surface because that's the side that works against the resistance of the cam and valves and the chain is pulled hard against it - that's also the critical side IRO wearing through the casing into the water pump jacket.

So even though it's more work to replace the guide and tensioner, I strongly recommend that it gets done. These components are normally due for replacement every 100,000 to 120,000 km's. Using a split-link to thread the new chain onto the sprockets without replacing the guide and tensioner is being short sighted IMO but using a split link to fit a new chain while replacing all the components does have the small benefit that you don't have to worry about timing marks - just fit the chain last when the new guide / tensioner are already in place and feed it down on the side of the guide and turning the motor at the crank.

Thanks guys, to be honest, I am not sure when it was done. A few months back when I replaced the cam I checked the chain tension and it look OK. to be honest I might go ahead and do the whole gosh darn thing. So Oom Andy, do you recon Toyota will still sell all the parts required? If not is there another brand or kit that you would recommend?

Thanks for the help so far.

Toyota still keep the kits.

Oil Pump

How would it make a knock Louis? - out of interest..

Your oil pump gives the oil pressure

So I phoned Toyota and got a quote for timing chain kit R2500+- Oil Pump R1800+-. I then swore a little and went to Ebay. Found pretty much the same kit with metal guides here, https://www.ebay.com/itm/371349676335. Shipping included for just under R1000. I then though I might take a look and see what else is for sale.https://www.ebay.com/itm/361407228897 & https://www.ebay.com/itm/140514093637 And I even sourced an american instrument cluster https://www.ebay.com/itm/22r-turbo-22rt ... itleDesc=0 with oil pressure & battery charge indicators all neatly tucked into the existing cluster, sigh!!!! Why didnt they do the same here in ZA.

Yes its shame how Toyota SA can rip one off. Here and there I Imported stuff too from the Us. Some things Toyota SA told me its not been made anymore...

Luke, can you please advise on how you will connect the oil pressure gauge to the existing oil pressure sensor? I have an old gauge from a stout that I would like to connect up so I have a proper pressure reading instead of just an indicator light. Thanks!