Ticking/rattle under throttle

[WarChild007]

Hi,

I hope someone can help.
I've got a rattle but can't identify where it's coming from.
It sounds light, not deep in engine. You can't hear it at idle but about 1500rpm to 2500 rpm it rattles, not on run down but only under throttle.

I thought it may be the timing chain or tensioner. It looks like the tensioner is leaking oil but I'm not sure it's causing the noise.

Is there anything in the intake/exhaust system that may rattle under acceleration? I'm wondering if it's this as it's only when throttle is open and not when the engine is off throttle or when revs drop.

I've done an engine flush and oil change also put some injector/egr/ engine cleaner in the fuel.

It's 2005 and covered 100k miles.

[Wilky1974]

..... have you checked the exhaust heat shields? When I first got my MR2 I had a similar rattle.  s:) s:)

[Joesson]

Undefinable rattles are very often found to be the exhaust heat shields, around the bend from the manifold to the cat also those along the cat.
Some remove them, others repair them.
If you search heat shields you should find some suggestions.
I removed them completely, de rusted them with a powered wire brush and refitted them with exhaust clamps  around the manifold flange and new nuts bolts and washers on the rest of it.
A quick cure is said to be stuffing  wire wool between the shield and the cat and holding it all together with  large jubilee clips.
Each to there own.

[The Other Stu]

A +1 for the heat shields. Mine was rattling when i bought it at exactly 2000RPM.

Was the cat heat shield - it had no bolts on at all.

[WarChild007]

I'll have a look and see, would it be notably rattly to touch / poke with a spanner?  
two garages have had it and checked it over, one thinks it's the chain the other three vvti. Booked into Toyota in a couple of weeks but if I can save 70 quid by putting a clip on a heat shield that would be good.

Any other thoughts if it's not the heat shield?

[WarChild007]

Seems strange that it's only on throttle and most noticeable between 1.5k and 2.5k rpm after that it flattens out.

[The Other Stu]

Well, like I said, that's exactly what mine did.
Take the nappy off and get someone to rev it whilst you poke a screwdriver about.

Have a search through the forum - I don't think that's what the chain rattle sounds like?

[mrzwei]

Seems strange that it's only on throttle and most noticeable between 1.5k and 2.5k rpm after that it flattens out.

No, that would be a typical symptom.

If you're feeling brave then get someone to rev the engine while you hold a long screwdriver or metal bar firmly against the heat shield. If the rattle goes then you know the problem.

Trouble is, it's difficult to diagnose without actually hearing it.

[James and his MR2]

Thats the same rev range I though mine was rattling, under say half or more throttle, as it goes I think its just my exhaust, the standard exhaust really does sound terrible if thats the case

[WarChild007]

I've had the exhaust and heat shields checked at kwik fit, not mechanics i know but they are helpful and let me look at it with them and it's not the heat shields.

They had four of their guys looking at it and decided they don't know what it is but it's internal and at the top of the engine.

So that agrees with the other two garages. I went back and spoke to the original garage and he explained why he thought it was either the chain or the vvti system and not other things. But it seems like these are pretty bullet proof as there isn't much online about them going wrong.

I've taken the ocv out and the filter below it and it all looks clean.

[krazysteve]

I'll have a look and see, would it be notably rattly to touch / poke with a spanner?  
two garages have had it and checked it over, one thinks it's the chain the other three vvti. Booked into Toyota in a couple of weeks but if I can save 70 quid by putting a clip on a heat shield that would be good.

Any other thoughts if it's not the heat shield?

Garages , all they see is ££££'s   charge you a small fortune for parts and labour, fit a jubilee clip on the rattling shield.   Mr "T" will have your pants down...
Does it go quiet with foot on clutch?
Flexi pipes on cat, cat breaking up, auxilary belt tensioner loose sticking?  Don't forget the heat shield on the inside of the precats,  Joint from main cat to silencer, bolts rusty conical seal worn.

No members near you? cast an eye?

 l viewtopic.php?f=11&t=58978 l

[WarChild007]

I've used the garage for many years with all of my cars at one point or another and trust them. It was them that suggested I take it to Toyota to get it diagnosed before doing anything more in depth.

Can't find a rattling Heathfield to put a clip on.

No it doesn't go with clutch down. Only thing is it's quieter or not there when engine cold. I'll try to get a sound clip of it.

[Carolyn]

As the sound changes with engine temp, that leads me to suspect it's related to the viscosity of the oil.  Two sounds that will get louder as the oil thins are chain tensioner or (I hope not) rod bearing.
Worth getting you hands on a stethoscope to pin down the location.  I dealt with a rod bearing that did sound as though it was coming from higher up and it was loudest at a steady 2-3,000 rpm.
Did the car come into your possession with this rattle?

[WarChild007]

As the sound changes with engine temp, that leads me to suspect it's related to the viscosity of the oil.  Two sounds that will get louder as the oil thins are chain tensioner or (I hope not) rod bearing.
Worth getting you hands on a stethoscope to pin down the location.  I dealt with a rod bearing that did sound as though it was coming from higher up and it was loudest at a steady 2-3,000 rpm.
Did the car come into your possession with this rattle?

Not thought about rod bearing. Tensioner is fairly easy to change and about 40-50 from Toyota. May try that first.
A stethoscope would be handy.
Other signs of a rod bearing?
Yes we've only had it a week.

Garage we got it from said they can take it to a mechanic they use but at our cost. I've got it booked in at Toyota, if it's something like the tensioner then we'll keep it but rod bearing sounds expensive.

I spoke to the garage that serviced it over the last few years and they said it started about October last year but the previous owner didn't want to spend the money on diagnosing it as they said if felt fine to drive. It's also not got worse with time.

Looks like there is or was an oil leak around the tensioner.

[Carolyn]

That's a reasonable approach.  As it hasn't got worse, a rod bearing seems unlikely.  They do get damaged by very enthusiastic driving round long right-handed bends.  If the oil is a bit low, the pick-up can sick air momentarily and do a bearing.  
The only symptom I found was the rattle.  Until, that is, I dropped the pan and inspected the bearings. The engine ran fine and still had power.
There are other parts in the timing gear (such as the VVTI) hub that can do an oil-pressure related rattle, but the tensioner it a real possibility.
They all leak past the O ring sooner or later, but that is not a symptom of a worn tensioner, just a crappy O ring.
Stethoscopes are on EBAY for around a tenner.  Handy tool to have around for all kinds of squeaks and rattles, like pulleys, belt tensioners, alternators....
Toyota service departments can vary in quality.  I'd want to try to pin it down before committing to Toyota.

[Smcknighty]

Rattle under throttle - is there a baby in the passenger seat? Stethoscope - cut down piece of hose pipe works well?


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[WarChild007]

That's a reasonable approach.  As it hasn't got worse, a rod bearing seems unlikely.  They do get damaged by very enthusiastic driving round long right-handed bends.  If the oil is a bit low, the pick-up can sick air momentarily and do a bearing.  
The only symptom I found was the rattle.  Until, that is, I dropped the pan and inspected the bearings. The engine ran fine and still had power.
There are other parts in the timing gear (such as the VVTI) hub that can do an oil-pressure related rattle, but the tensioner it a real possibility.
They all leak past the O ring sooner or later, but that is not a symptom of a worn tensioner, just a crappy O ring.
Stethoscopes are on EBAY for around a tenner.  Handy tool to have around for all kinds of squeaks and rattles, like pulleys, belt tensioners, alternators....
Toyota service departments can vary in quality.  I'd want to try to pin it down before committing to Toyota.

Thanks for the information.

I've booked it into Toyota but as you say, I'm trying to determine what it is myself, without spending too much on it.

Am I right in thinking that if I unplug the spark plugs one by one and run the engine each time I can see if the rod bearing has gone if the noise stops on one plug.

If that doesn't show anything, I think I'll try the tensioner.

[Carolyn]

At the very least the noise should change.  Not so sure about revving it with a plug out and an injector spraying fuel though.  I shouldn't have scared you with the rod bearing idea.  Do the tensioner and see how you go.  
Engine noises are a pig to track down.  If you can determine roughly where it's coming from (a bit of hose in one ear doesn't really work) you can distinguish top from bottom at least.
Putting a recording up on the net really doesn't work either, I'm afraid.  If I heard it 'in the flesh' I could pretty much tell you what it is as I've been through it quite a few times on MRs and other cars.  I'd certainly recognise a rod bearing.

[WarChild007]

At the very least the noise should change.  Not so sure about revving it with a plug out and an injector spraying fuel though.  I shouldn't have scared you with the rod bearing idea.  Do the tensioner and see how you go.  
Engine noises are a pig to track down.  If you can determine roughly where it's coming from (a bit of hose in one ear doesn't really work) you can distinguish top from bottom at least.
Putting a recording up on the net really doesn't work either, I'm afraid.  If I heard it 'in the flesh' I could pretty much tell you what it is as I've been through it quite a few times on MRs and other cars.  I'd certainly recognise a rod bearing.

Just listened to a few YouTube clips and the sound seems louder and more regular.

I'll get a tensioner tomorrow and see if it solves it.

Thanks for your suggestions

[Carolyn]

Take a look at 'Understanding your chain tensioner' in the How-to's.  All you need to know about the universe and everything.

[WarChild007]

Hi, I have replaced the tensioner and it still knocks,  I disconnected the electrical connector from the top of the drivers side plug and started it up.  a host of lights came up but there was no knock.  Does this deff mean the little end or is there potential for something else?

[Carolyn]

Time to drop the pan and take a look, I'm afraid.
Edit:  I've sent you a personal message (PM).