engine knock

[hilux67]

Hi, I have a Toyota Hilux 2004, 420. 000 km 2.4 diesel turbo D4D, the engine knocks on start up, for a few seconds, the strange thing is, it only does it on a hill. any ideas . Thanks.

[E-bmw]

Does it matter whether the car is pointing up/down the hill?

Have you looked at it when it is started in case it is engine vibration due to an engine mount?

[hilux67]

Hi thanks, when facing down hill it knocks, pointing uphill ok, took me few weeks to see the pattern, oil level appears to be ok, just checked it again, on the higher mark on the stick

[hilux67]

Hi thanks, when facing down hill it knocks, pointing uphill ok, took me few weeks to see the pattern, oil level appears to be ok, just checked it again, on the higher mark on the stick, engine mounts seem ok, smokes for a few seconds, sounds like the cam knocking.

Edited by hilux67 on Saturday 17th May 13:26

[GreenV8S]

I wonder whether it could be due to worn valve stem seals allowing oil pooled on the heads to drain into a cylinder, or something like that. Does it matter how long it's been left standing?

[hilux67]

Yeah, on a hill for 5 min ok, left for an hour or so it will knock for about 2 seconds

[GreenV8S]

hilux67 said:

Yeah, on a hill for 5 min ok, left for an hour or so it will knock for about 2 seconds

That supports the theory.

[Smint]

The 3.0 litre engines can suffer with injector seal blow by, which especially on vehicles that have irregular oil changes can end up with carbonised oil clumps blocking the pick up strainer causing terminal engine damage, that's one check i'd be doing on yours to rule it out.

On Prado style Landcruisers with the same engine you can see the pick up strainer because its directly over the oil drain hole hence those of us in the know tend to leave the oil to drain for several hours or overnight to check the strainer visually.

Far as i know the Hilux sump design is different so an endoscope connected to your phone/laptop might be needed.

One other thought, have you physically checked yourself the amount of oil required for an oil change, proving the dipstick is correct for the vehicle, i'm assuming here you haven't owned the vehicle from new so a remote possibility the dipstick has been replaced at some point and isn't correctly marked, yes its a wild card.

[hilux67]

Hi guys, thanks for the replies, had it 4 years, and servicing is by Toyota, it's due for a service, so may take it in earlier. Going to be fun explaining the problem in spanish, Would appear to be the right dipstick, and oil level a bit too high, as I put another litre of oil in yesterday, just above the top mark on stick. At least I now have some information on possible causes. Thanks very much.

[hilux67]

GreenV8S said:

That supports the theory.

Never heard of this before, live and learn eh ! Thanks.