Hi all,
I've got a strange noise coming from the engine most noticeable when the revs are 1500+ (during acceleration, not coasting), from inside the car it sounds like a reasonably mid/high pitch rattle. If I listen in the engine bay it is definitely noisier around the right hand side of the engine, I think this has slowly got worse over the last year or so. I have changed both the auxiliary belt tensioner and idler pulley recently but neither has rectified the problem. I'm going to check the timing chain tensioner next (once I get a new o'ring) but could this cause that sort of noise?
Thanks
How many miles are you on?
Is it defo coming from the engine? The classic rattle with acceleration under load is due to loose heatshields around the downpipe and main cat. Broken seam welds are the usual cause.
If you haven't yet checked these, they're worth a look if only to rule them out.
Of course, if its engine-related, a bit more info on mileage, circumstances of when it does/doesn't rattle etc would be handy.
I'm on about 85k, and it's definitely not the heat shields - all of the standard exhaust is in my shed :-) :-) :-)
I think the noise is always there just more pronounced under acceleration.
Sent from my XT1068 using Tapatalk
Engine noises!!! So hard to pin down. It's worth spending a tenner and getting a stethoscope. Then you can listen to all the bearings on the belt system, including the alternator. Bit fiddly and has to be done carefully, 'cos it will all be in motion. If you don't find it there, then you can place it on various parts of the engine to see where it's loudest.
You can rev her up by manually tweaking on the throttle cable - you have to reach well in there, but it's easy enough once you've got it located.
If it IS coming from the engine.... possibly timing chain (unsusual but can happen, especially if the tensioner has been incorrectly installed) or rod bearing (more common as a result of track-day style driving). I'm not trying to put the fear of god into you, as neither is a total disaster.
Any way, if it is in the engine, you will only really pin it down to top or bottom (sound gets transmitted round an engine in misleading ways), then it's time to open the engine up a bit and inspect stuff.
Agree with Carolyn. So hard to pin down.
Had the same problem, mine a while back. Ended up being the water pump.
Hope you are able to find the culprit and it's not too serious. s:) :) s:)
Sent from my Nexus 6 using Tapatalk
After a manic few months I've finally got back to looking at this now!
I've performed a compression test approx 180 across all four cylinders, when I was doing this I didn't remove the plugs on all cylinders just loosened them to release some of the pressure - to avoid any dirt being pulled in - and I can't be sure on no.4 but when testing the other cylinders there was a very noticeable metallic knock when spinning the engine over.
I've tried poking about when the stethoscope but not really been able to pin point the location of the noise - just normal whiring sounds round the drive belt.
The timing chain tensioner all looks ok - spring and ratchet are fine.
At idle the noise is not noticeable however increasing the revs to approx 2500rpm it sounds like a diesel - looking at the you tube vid's I think a spun rod bearing is very likely. I've now got the oil drained and the sump off I thought no.4 had play but in rotating the engine to check the others - all of which seem ok - I can't find any movement now. Can anyone give me some tips on how to check for play or do I need to remove the caps and check the bearings themselves? If one has spun I guess it would be a good idea to replace them all?
Thanks
Remove the caps. Start with#1. Yes do them all. Check the crank for scratches. If you've spun one (or it looks tatty) there will be a little white-metal pick-up on the journal, which can be gently polished of with fine wet and dry.
Thanks for the quick reply, fingers crossed it's not scored the crankshaft and it's an easy fix :-) :-) :-)
Sent from my XT1068 using Tapatalk
I've just quickly pulled the caps, they all look pretty good, just normal wear marks. I'll try and have a look at the crank tomorrow - hopefully it'll warm up a bit! Any other suggestions?
Sent from my XT1068 using Tapatalk
Ideally there shouldn't be any wear that's obvious. Try some plastigauge and see what the clearances are. Specs are : 0.028 – 0.060 mm (0.0011 – 0.0024 in.) Perhaps post a pic of the shells?
Check water pump, belt tensioner and idler pulley for play. (Really shouldn't be any).
Measure the valve clearances, Inlet: 0.025 – 0.060 mm (0.0010 – 0.0024 in.) Exhaust 0.030 – 0.065 mm (0.0012 – 0.0026 in.)
If all ok, then measure the chain. With the chain tight between the sprockets, 16 links should measure no more than 122.6mm
Good luck. I hate chasing engine rattles.....
Thanks for all the info, I'll get a picture of the shells on later today. Is it worth investigating the main bearings as well?
I've changed both the belt tensioner and idle pulley, but I'll give the water pump a try. Then on to the valves and chain!
Thanks again I'll let you know how I get on :-) :-) :-)
Sent from my XT1068 using Tapatalk
Like your attitude. You just get on and do.
Main bearings are highly unlikely, plus it's a full-on engine out and dismantle job.
My money is still on rod bearings.... but guessing is no substitute for inspection.
If you have verniers you can check your shells by comparing the thickness at the centre to the thickness at the ends. Should be near identical.
Press on buddy, you'll get there.
Not much else to report, the local motorists shop doesn't know what a plastiguage is! So I'll have to wait to next week.
Hopefully it'll warm up a bit and I can check the water pump and valves.
Meanwhile here are the rod cap pictures
No 1
m https://goo.gl/photos/KxqfV4FvCBvsz2X77 (https://goo.gl/photos/KxqfV4FvCBvsz2X77) m
No 2
m https://goo.gl/photos/PAffhqtrw27RuRDg9 (https://goo.gl/photos/PAffhqtrw27RuRDg9) m
No 3
m https://goo.gl/photos/1KbqHWdAaRawR6Gk7 (https://goo.gl/photos/1KbqHWdAaRawR6Gk7) m
No 4
m https://goo.gl/photos/XjKHHM1bAAxdVDMT6 (https://goo.gl/photos/XjKHHM1bAAxdVDMT6) m
Hope they're some use!
Sent from my XT1068 using Tapatalk
They look worn to me. Seen much worse, but they are showing wear. Try measuring them, I suspect there'll be quite a difference between the middle and the end.
If you go the new bearing route remember they are not usually all the same/standard size.
they have a number stamped on the shell outer for what toyota fitted.
I'll have a measure and see, but having got this far I will probably replace them.
Thanks for the reminder about sizing I'll make a note of them before ordering.
Sent from my XT1068 using Tapatalk
I'd replace them too. But do still measure, so we can pin down the rattle.
I've pulled the bearings ready to measure them, giving them a good clean its quite clear that they all show quite a lot of wear - I can add some more pictures if anyone is interested. Unfortunately I can't find my vernier so it'll have to wait until I get to work tomorrow....
I also managed to have a measure of the valve clearances before I lost all feeling in my fingers, I've not got precise measurements I just did a quick go, no-go with the min and max limits (thanks Carolyn for the limits) and they are all within spec. Hopefully a set of replacement bearings will sort the problem and I'll be knock free :-) :-) :-)
As I am already this far into the engine do you think it would be worth removing the head and checking/replacing piston rings and possible replacing timing chain, oil/water pump or would it be best to leave well alone as I've never had any issue with burning oil?
Removing the head with the engine in the car can be done, but it's an absolute pig of a job. You've only got the sump off, so you don't have a huge amount of time invested.
To reassure you, I had a rattle in a face-lift engine that was also a pig to track down. Came on at about 2500 rpm, just like yours. Bad rod bearing on #1 and the others not brilliant.
Given that, I'd polish up the crank (get any white metal build-up off) with fine wet and dry. (There's a trick using a bit of string over some of the wet-and-dry to get to the top of the journal.) Put in the new shells and get the pan back on. I'm 90% confident you will have cured it.
The timing chain is rarely a culprit.
If you want to do a re-build at a later date, pull the engine out. It is so much easier to do it that way, honest! (and you get to put a new clutch in at the same time).
To be honest I'm quite happy not to make life difficult for myself, so if I can avoid stripping the engine completely that'll be great :-) :-) :-) I do need to replace the clutch at some point - it can't hold the torque from the turbo - but hopefully that'll last until it's warmer!
Sent from my XT1068 using Tapatalk
I've measured the bearings with a micrometer in three places round the bearing (A) the lug end (B) the middle (C) the non-lug end
1Bottom A = 1.452 B = 1.498 C = 1.445
1Top A = 1.433 B = 1.495 C = 1.442
2B A = 1.442 B = 1.497 C = 1.437
2T A = 1.513 B = 1.494 C = 1.437
3B A = 1.442 B = 1.490 C = 1.455
3T A = 1.453 B = 1.492 C = 1.442
4B A = 1.454 B = 1.501 C = 1.454
4T A = 1.442 B = 1.488 C = 1.440
I was a bit surprised that the centre of all of them measured thicker than the tops, but I had to use a drill blank to follow the radius so maybe that led to some inaccuracy.
Here is a proper picture of all the bearings
m https://goo.gl/photos/KztAfdUj8yJutytV7 (https://goo.gl/photos/KztAfdUj8yJutytV7) m
It's clear to see that the top bearing shows a lot more wear than the bottom on all cylinders so hopefully it's just wear and tear. I can't think of any more checks to do so I guess it's time for some new bearings, I assume that the number stamped on the bearing and rod cap is the size (three 2's and a 3)?
Here is the process I was going to use when fitting them, what do you think?
1) clean/polish crank with fine wet and dry and a shoe lace
2) Clean everything very thoroughly
3) Fit upper and lower shells (lightly oil rod bolt threads and heads)
4) Check clearance with plastigauge
5) Strip clean lubricate
6) Re-assemble
Thanks :-) :-) :-)