Rattling whistle on V6 during moderate acceleration........!

[bongodonkey]

Hi all,

I've noticed that me bongo has a distinctive 'rattling whistle' during moderate acceleration whilst on lpg.

On petrol he is fine!

The sound is almost like a turbo whistling away and even with my lack of automotive knowledge I know that the V6 doesn't have a turbo!

Any ideas what it could be?.....I've got the bongo booked into the 'vets' on 22 Oct. There is no loss of power or any escaping gas or anything loose or untoward underneath t'bongo either

I'm hoping either I'm paranoid (so the voices say) and/or the bill is not obscene......the last one came in at £650 in Feb......which was nice!

[lpgimports]

which make LPG system? have seen prins systems where the diaphragm in the vapouriser kind of resonates at certain RPM's

[bongodonkey]

It's a ROMANO system.........

Would the injectors be an issue? As that's what the vet reckons subject to a test drive next weekend!

[bongodonkey]

Well me bongo's trip to the vets was not totally successful to say the least!

Dave had him up on the ramps and took the bottom plate off to carry out investigations about the whistle/rattle.

After a full engine and separate LPG diagnostic he couldn't find owt. The whistle/rattle is whether the engine is running on gas or petrol and comes on over 2200 rpms and drops off once you take the pressure of the accelerator.

Daves cannot find the source, though he mentioned that the timings is well out and that it's possibly the 2 rollers that route the cambelt on the face of the engine...... .

The bongo is booked into the vets in a few weeks due to work........the estimate is approx 5 hours labour and parts.....hopefully that is the problem rectified.....

Anyone got any ideas or come across this symptom before?...

[Ron Miel]

Well me bongo's trip to the vets was not totally successful to say the least!

Dave had him up on the ramps and took the bottom plate off to carry out investigations about the whistle/rattle.

After a full engine and separate LPG diagnostic he couldn't find owt. The whistle/rattle is whether the engine is running on gas or petrol and comes on over 2200 rpms and drops off once you take the pressure of the accelerator.

Daves cannot find the source, though he mentioned that the timings is well out and that it's possibly the 2 rollers that route the cambelt on the face of the engine...... .

The bongo is booked into the vets in a few weeks due to work........the estimate is approx 5 hours labour and parts.....hopefully that is the problem rectified.....

Anyone got any ideas or come across this symptom before?...

The cambelt idlers (rollers) do sound like a possible cause - and maybe, if the timing's out, the (hydraulic) cambelt tensioner not doing its job properly could be a root cause of any problems in that area. Just had to have mine changed - and also did the cambelt (not really due but replaced early for good measure and not much add-on cost) while we were in there. The V6 cambelt tensioner can be hard to source and/or pretty pricey. If you find you do need one, and PM me, I can point you at a competitive source. I suppose that if the cambelt itself is worn, has dropped a tooth or three, and/or has loose bits flying about, that could itself whistle. There was a topic on here recently, with photos of a V6 cambelt in that sort of state, caught just before it would surely otherwise have failed with disastrous effect. Don't want to create unnecessary panic but, with any doubts about what might be going on in the cambelt area, I would be very uncomfortable about leaving it "a few weeks" before getting it stripped down to check it out - work or not, I'm afraid. Presumably, you know that a cambelt failure would wreck the engine, giving you a very large bill to get back on the road again?

[bongodonkey]

Fortunately we have a second car and I've driven about 1000kms on the bongo since I've noticed the problem.

The bongo could be put into the stable and left - though I'm loath to do that as no bongo likes to be stood still - even for 4 or 5 weeks!

Dave is away for the next couple of weeks on a well earned rest, and I'd rather have the maestro work on it as he knows them so well, rather than his lads. I must stress that his lads are extremely capable and this is no reflection on them just me being a bit precious about me bongo.

The parts - new cambelt and 2 rollers are £130 and the rest is labour, so I've got to put some pennies by for that. I'm just really chuffed it's such in time for Christmas

Still, I suppose that it's never really a good time is it!

Cheers for your info Ron Meil, I'll keep an eye and remember this to Dave when I take t'bongo in again on 26 Nov.

[rita]

Well me bongo's trip to the vets was not totally successful to say the least!

Dave had him up on the ramps and took the bottom plate off to carry out investigations about the whistle/rattle.

After a full engine and separate LPG diagnostic he couldn't find owt. The whistle/rattle is whether the engine is running on gas or petrol and comes on over 2200 rpms and drops off once you take the pressure of the accelerator.

Daves cannot find the source, though he mentioned that the timings is well out and that it's possibly the 2 rollers that route the cambelt on the face of the engine...... .

The bongo is booked into the vets in a few weeks due to work........the estimate is approx 5 hours labour and parts.....hopefully that is the problem rectified.....

Anyone got any ideas or come across this symptom before?...

The cambelt idlers (rollers) do sound like a possible cause - and maybe, if the timing's out, the (hydraulic) cambelt tensioner not doing its job properly could be a root cause of any problems in that area. Just had to have mine changed - and also did the cambelt (not really due but replaced early for good measure and not much add-on cost) while we were in there. The V6 cambelt tensioner can be hard to source and/or pretty pricey. If you find you do need one, and PM me, I can point you at a competitive source. I suppose that if the cambelt itself is worn, has dropped a tooth or three, and/or has loose bits flying about, that could itself whistle. There was a topic on here recently, with photos of a V6 cambelt in that sort of state, caught just before it would surely otherwise have failed with disastrous effect. Don't want to create unnecessary panic but, with any doubts about what might be going on in the cambelt area, I would be very uncomfortable about leaving it "a few weeks" before getting it stripped down to check it out - work or not, I'm afraid. Presumably, you know that a cambelt failure would wreck the engine, giving you a very large bill to get back on the road again?

Hi Ron,
I was always under the impression that engines with HLA were non interferance type.Does the v6 in the bongo actualy have an interferance type engine.??

Cheers.

[Ron Miel]

Good luck Oz & Sam.

I would definitely keep the miles off the Bongo though, until "Dave" (?) has had the cambelt covers (2) off, to see what's really going on in there. What concerns me is that you've apparently got a diagnosis and a firm parts quote, without any visual confirmation/testing.

The recent fault on mine was initially diagnosed (only by ear, albeit by one of the best reputation V6-savvy "Bongo-friendlies" going) as a water pump bearing on the blink. Fortunately, to change the water pump on the V6, you have to open up the cambelt system and, when that was done, the cambelt hydraulic tensioner was found to have failed, with the cambelt grossly over-tensioned - described as "snapping point"! We can only guess how close it was but that would eventually have caused premature belt failure, as well as probable idler and/or cambelt/crankshaft oil seal problems. Lesson - don't change the cambelt without the tensioner, anyway, no matter how good the tensioner looks at the time. My cambelt (but not the tensioner) was changed at 66,000 km when we bought the van, and had still only done 105,000 km.

Still changed the water pump to be on the safe side and as it apparently had a small coolant weep (not that I was losing coolant) - but was very relieved to get the cambelt and tensioner replaced before serious damage occurred. The unhealthy engine sounds originally causing alarm were fully cleared by the total job but at that stage neither the garage nor I could positively confirm which failing component had really caused them. I suspect it was the cambelt system though, not the water pump.

Hadn't said so before but our own trip to the garage was also triggered by a high pitched engine sound on moderate acceleration, on either fuel. The sound was high pitched enough that my 74 year old ears couldn't hear it, from the driver's seat, and it took the ear of "she who hears all", to pick it up first. When I then got down under the nearside, and she revved the engine, I could then hear a very high frequency noise, which I suppose you could describe as a whistle - but I could also hear a high speed rattle or grinding noise component in it. Result - straight off to our Bongo-friendly, not exceeding 50 mph on the 40 mile trip, and am so glad I did that, even though we delayed a planned long Bongo trip more than three weeks, in the process.

[Ron Miel]

Hi Ron,
I was always under the impression that engines with HLA were non interferance type.Does the v6 in the bongo actualy have an interferance type engine.??

Cheers.

Yes, it does rita - and a 100,00 km/62,000 miles cambelt service replacement period, as a result. David

[bongodonkey]

Cheers for the replies.

The cambelt has been changed twice since we've had the bongo.

First was on the initial import by the company that we bought off and the second was in Feb this year when camshaft/crank seal went on the face of the engine. We were in Scotland at the time and the only bongo garage we could find was one that had only come across diesels!

Anyhow, Dave is the nearest bongo friendly garage to us and he has been really good to us in the past with servicing and the like.

It will be feet off the gas and the bongo laid up until I"m back from being away with work!

I will mention the hydraulic tensioner and the water pump to be checked - though Dave is through.

Hopefully it will be a straight forward fix. The rattle/whistle is clearly audible on both systems so it's not the LPG that's affecting the engine. The fact that the timing is out doesn't help either!

I will just have to wait out though if you come up with something else I'll be much obliged.

Cheers peeps!

[Ron Miel]

>
>
It will be feet off the gas and the bongo laid up until I"m back from being away with work!
>
I will mention the hydraulic tensioner and the water pump to be checked - though Dave is through.
>
>
I will just have to wait out though if you come up with something else I'll be much obliged.

Cheers peeps!

Only thing this peep would add is the observation that I'm pretty sure the water pump would be likely to just be a red herring, as I feel it was in my own case - and that was the point I was really trying to make. Even the best of them, and I'm now dealing with one of the best-regarded J5-DE V6 spannermen, can't reliably diagnose a fault under the cambelt covers accurately by just listening to it. So, it's a good move to lay it up until it's properly checked

Hopefully, your problem is just idler wear* as Dave has guessed but even an eventually seized idler could cause premature cambelt failure, and that's not something you want to risk. Did the Scottish garage give you any reason why they thought the oil seal(s) had gone? One reason can be a blocked crankcase breather, due to dirty oil not changed regularly enough, allowing gas pressure to build up behind them - but another one is incorrect belt tension applying undue sideways forces on the shafts running in them. So, yes the cambelt tensioner defo needs checking carefully but, as you say, Dave is sure to do that.

Even so, and I don't know what mileage yours has done overall, but if its much more than 100,000 km the question I might still ask myself, for the reason I spelled out before, is whether it will be sensible to pass up yet another chance now to prophylactically change the cambelt tensioner, even if it's apparently OK at the moment? Cost of a tensioner about £227.

[bongodonkey]

OUCH that much for the tensioner!!

We got our bongo with 82,000kms on it in Sep 2010......we've done just shy of 19,000kms since we've had it.

So, the cambelt was changed on import and when it was repaired in that Scotland.

The reason that the seal was replaced was that the other half noticed a big oil slick after the bongo had been parked up overnight.

So when we took it to the garage after a frantic 24hrs of searching (cheers to BF and Billy Bongo for sorting us out). When the garage had the bongo on the ramps, it turned out that the area around the seal had been 'filled' with some gunk. The garage owner was disgusted that such a bodge job had been done - as for a time line as to he couldn't say when the 'fix' had been done.

My intuition is that it was done in Japan to get it through the auction process; reason being is that when the cambelt is changed if the seal was seen to be leaking it is a very quick fix as the plate is off and the mechanic is there working on the belt change. The seal was only £25 inc postage, so I seriously doubt that the dealer and garage would scrimp on that!

Currently if it turns out to be any of the rollers with the belt thats an approximate bill of £400, with that tensioner you mentioned thats another hour of labour and the part, bumping the bill up to approx £700 in total.......yesss (pumps fist in air with joy!!)

AAAGGGGHHHH

I hope not, as that will have pushed the garage bill for our bongo for the year to almost £1400 ......not on, even if I loves him to bits.

[Ron Miel]

Judging by my experience, and that of several other V6 peeps, it's at about the mileage where they typically do cost a bit, in order to renew much of that front end system - after that, given TLC and due maintenance, it should then give another long stretch without a repetition. Pity you got caught by the bodge though. I'm running at a bit over the £1,000 mark myself, so far this year, at 105k km, but it's mostly stuff I would expect at this mileage.

Sorry you're faced with it though.

[bongodonkey]

Cheers pal - I suppose that little bit of pain is to be expected - though I was toying with the idea of asking 'what else' could be done out of rote (same as what you did), but not if the bill is bigger than Liberia's deficit!

Will hope for the best - you never know it could all be much ado about nowt - then again, check that squadron of flying pigs!

[Ron Miel]

Has Liberia got a deficit? Nowadays it's the "rich" countries of the west, ourselves included, which are painfully in hock. We're expected to pay back but Liberia isn't - perhaps that's the difference.

Yes, be positive and ignore me - it's just the idlers need a bit of grease!!