Start-up engine knock, 2017 2.8 Auto GXL

[gazzasa Lurker Find all posts View Profile Close gazzasa]

Hello brains trust, new member, long-time reader and first post. Great forum and the wealth of knowledge is fantastic! I can’t wait to win the lotto and start fitting out my own 2.8 GXL :-)

I’m hoping for some guidance or thoughts with a concern I have in my stock 2017 2.8 GXL auto.

The concern is a start-up knock which happens upon start-up. It is a singular knock early in the start-up cycle. The knock can be heard and felt through the steering wheel and brake pedal. It started after about 3000km last winter and continues to get worse. I’ve done 30,000km and the knock happens every start-up in the morning and every start-up after been driven and then allowed to sit for 30 – 40 minutes.

I’ve raised my concerns with the selling dealer and Toyota technical. They have investigated and have commented it’s a normal start-up characteristic of the model 2.8’s fitted with active engine mounts. I’ve driven a few 2017 2.8 GXL’s and the newer 2018 2.8 GXL’s and all haven’t displayed the same singular knock upon start-up.

Does anyone have any experience with this type of knock or perhaps could shed some light on the active engine mounts and a possible remedy…

[120D4D Avid PP Poster! Find all posts View Profile Close 120D4D]

The engine mounts are pnumatic and when operating correctly make start-up and shut-down of the diesel very smooth.
The mount itself is inexpensive to replace if faulty, but the labour to change one (or both) will certainly will not be pleasant!!

Get them changed before your warranty expires, if that is your problem...

[gazzasa Lurker Find all posts View Profile Close gazzasa]

Thanks for the quick reply 120D4D.
Do you know if there is a vacuum test or an ECU error code generated if the mounts vacuum has failed?

[120D4D Avid PP Poster! Find all posts View Profile Close 120D4D]

Not sure but i'd imagine the dealer can test them.

[Two89w Member Find all posts View Profile Close Two89w]

I know this is an older post however my 2018 does the same thing ,but only on cold start up.

[gazzasa Lurker Find all posts View Profile Close gazzasa]

Update - long fight and many hours back and forth but have had replacement 'new and improved' active engine mounts fitted - now worse than before...

[nudgebar Member Find all posts View Profile Close nudgebar]

that bites . you dont think its the timing chains causing any noise ? thats a known problem.

[gazzasa Lurker Find all posts View Profile Close gazzasa]

that bites . you dont think its the timing chains causing any noise ? thats a known problem.

Not sure mate, but I'm well over it as yet another issue has started up, DPF failure and blowing white smoke, all in just over a year old and 37800km later, oh what a feeling NOT.

[nudgebar Member Find all posts View Profile Close nudgebar]

you did well getting 37k out of the DPF , i had timing chains and DPF replaced by 27k , two years old.

[gazzasa Lurker Find all posts View Profile Close gazzasa]

you did well getting 37k out of the DPF , i had timing chains and DPF replaced by 27k , two years old.

Sorry to hear mate, thats just crazy, how did you diagnose a timing chain issue?

[nudgebar Member Find all posts View Profile Close nudgebar]

it was a bit fateful really - i let my mate borrow the car for a couple of days , and happened to be standing directly in front when he started it , and i heard motor rattle for a few seconds. i had not heard it before and asked Toyota to inspect at next service , thinking it was a buggered injector or worse still an oil pump. All timing related parts were replaced , took around 8 days while the engine was removed / refitted and extra bits had to be ordered . Any other time and i would not have noticed anything wrong. As for the DPF , well i was getting continuous DPF full messages so they replaced it in about a day

[gazzasa Lurker Find all posts View Profile Close gazzasa]

it was a bit fateful really - i let my mate borrow the car for a couple of days , and happened to be standing directly in front when he started it , and i heard motor rattle for a few seconds. i had not heard it before and asked Toyota to inspect at next service , thinking it was a buggered injector or worse still an oil pump. All timing related parts were replaced , took around 8 days while the engine was removed / refitted and extra bits had to be ordered . Any other time and i would not have noticed anything wrong. As for the DPF , well i was getting continuous DPF full messages so they replaced it in about a day

Great that you caught it in time. Please tell me it doesn't sound like a bicycle chain being pulled out of a tin can on start-up? I've heard this a few times now in my attempt to capture the start-up engine knock, I thought it was perhaps a lower grade oil viscosity used it the last service and the result of a oil pick up issue after standing over night, but sounds like it's more sinister. Do you have any TSB info or parts list to share?

[nudgebar Member Find all posts View Profile Close nudgebar]

actually it does sound like what you said - pulling a chain out of a tin can whilst scraping against the side of the tin , for want of a better description lol. sometimes at idle i would hear the odd scrape / rattle which was a separate noise to the usual subdued diesel noises. I took a quick look on the Hilux forums and the same scenario is mentioned there as well so its definitly a known issue although less common than DPF failures. I'll cut and paste some info I have found over there providing its OK with this sites moderators.

[nudgebar Member Find all posts View Profile Close nudgebar]

reposted from another Toyota forum , if mods allow this -

DPR 703192 - Machining Fault in Factory Crankshaft Gear , Fit Upgraded Timing Chain Kit

TO1356611030 Guide , Chain Damper QTY 1
TO9672119017 Ring 4
TO9043006013 Gasket 4
TO1356211010 Damper , Chain 1
TO1356111010 Damper , Chain 1
TO1355911020 Slipper , Chain 1
TO1355911010 Slipper , Chain 1
TO1355211010 Gasket , Chain 1
TO1355011010 Tensioner Assy 1
TO1354011010 Tensioner Assy 1
TO1352111040 Sprocket , Crankshaft 1
TO1350711010 Chain Sub Assy , No 2 1
TO1350611010 Chain Sub Assy , No 1 1
TO1132811070 Gasket , Timing Chain 1
TO1121311070 Gasket , Cylinder 1
TO1117633010 Seat , Injection 4

i didnt keep any dealer paperwork for what was done , i presume its kept on thier system

[Rossi46 Lurker Find all posts View Profile Close Rossi46]

Did you manage to find out what the knock on start up was? I just got a 2018 Kakadu as a demo model, has 3500km on the clock and I notice a single knock on start up too. is it an issue or just part of the start up? I will be taking it back to Toyota for the 1 month check up soon so will get them to have a look too.