Many issues or just one?

[topbanana]

Hi All,

Our Bongo has just come back from the garage, following the flashing glow plug light problem. Its a 2002 diesel 4x4 fly by wire, and turned out to be the speedo chip. Having removed the chip and replaced the facia all seems well with that issue.

Its now developed a number of symptoms that were not there before, I'll try to describe them as accurately as possible, so any help would be appreciated.

On pulling away sometimes not always, either warm or cold, there seems to be a delay in engaging drive. Just a second or so where the revs rise slightly, but no movement. A bit more throttle, and theres a gentle thump, gear engages, and off you go.

Also sometimes, on pulling away, the engine seems to miss and hunt, with reduced power, then a little more throttle and off it goes.

The other problem is a noise. Under acceleration, between 2k and 4k revs, there is a gentle metallic grating/rattling and whining noise that gradually gets louder as revs increase, coming from the passenger side of the engine. It hard to describe the sound exactly.

Once its up to speed and in top gear, the drive is smooth and noiseless, even if you accelerate.

We've had it looked at today by a local Bongo friendly mechanic and he seems a bit stumped. The No.1 stud is ok, theres no soot, the ATF is ok, no loss of power, waste gate ok, and everything else that he could think of seems to be working.

Anyone any ideas, I know thats a lot of info!

Thanks

[Northern Bongolow]

the rattle could be the crankshaft pulley, these are a 2 piece rubber/steel bonded pulley, they can separate causing half to spin and half to spin at a different rev, this may also be the cause of the random revs issue. could also be the idler gear on the alternator belt/s tensioner, these again are known to fail at the bearing.
11-371 in the link below.
http://lushprojects.com/bongopartsmk2/c ... mgno=.html

it could also be the throttle position sensor, i think this one is built into the throttle peddle on this year, they are known to be easily disturbed.
41-aco in the link below

http://lushprojects.com/bongopartsmk2/c ... no=.html#4

[topbanana]

Thanks for the info.

Have something of an update.

The dealer who I bought it off was kind enough to come down tonight and take it for a drive. The rough gear changes did not manifest themselves, but he noise did.

Driving around with the passenger seat up revealed exhaust gas being expelled from around the turbo, on acceleration.

So at least he is acknowledging that there is a problem and has taken the vehicle back for investigation, and offered to change the ATF and filer free of charge.

So there may be more than one problem.

Would the no1 stud broken cause gas to vent?

[Northern Bongolow]

it may do, but ive not heard of a fly by wire set up breaking studs.
sounds like a good dealer, let him worry, and see what happens.

[topbanana]

Cheers for that, something of an update.

It came back today, following an ATF, and filter change.

The result is a much smoother drive, the hunting issue has disappeared, as has the noisy and abrupt gear change, so good news!

The 2k-4k noise is still there though.

Accelerating gently around town for eg, there is no noise at all. However foot down up hill, or accelerating towards 60mph, again produces a noise.

Its a gentle metallic scraping/rattle coming from the turbo area, that increases in volume, then when the car changes up, seems to peak, and then slowly subside, in both pitch and frequency, once the revs drop below 2k.

No loss in performance or anything, just this noise, like a heat shield rattling or something. Doesn't seem fatal, just very irritating!

Thanks for your help

[Northern Bongolow]

the turbo comes in just above 2k so could b related,but at the rate the turbo is spinning it sounds odd.
ive no experience in these turbo's but iv heard that the internals run very close to the outer casings, closer than the early ones so if it runs hot or a bearing is starting to wear the internals can touch.
is it better when fresh from a cold start ??. you could take the pipes off and see if its (coked up). if it is you could try carb cleaner but make sure its cold first or it could go on fire.

is the egr blanked off ??.

[windywatson]

This sounds to me like there's some end float in the turbo shaft/spindle. As you say the tolerances are very fine snd you don't need much wear for surfaces to come into contact and cause exactly what your describing. It wont be a particularly cheap fix, turbo swap or replacement and checking to ensure that the oil supply that lubricates it is ok. Perhaps the dealer has conveniently over looked this because of the cost?
Get the turbo checked out sooner rather than later. It's not to difficult, as once the inlet pipework is disconrcted you can usually get hold of the end of the shaft with long nose pliers and pull on it. If there's any movement back and forth then it needs sorting


cheers

[topbanana]

Thanks for the reply guys, given the experience of the last week, it think your both very close to the mark!

Full story (short version):-

Bought the vehicle in Oct last year, with 6 months warranty. Initially ok but found it very, very sluggish, under load when the engine was warm. Didn't see this on test drive, as it was only a few miles.

On replacing some instrument lights, a month later, I noticed the glow plug, (lamp and holder had been removed). Replaced both, then the glow plug light started flashing, when up to temp, and under load. It then goes into limp mode and is underpowered.

Dealer sent to 321, (under warranty), found "waste gate failed to open under pressure, code", replaced just about every solenoid or sensor! Then noticed that the solenoid on the left, under passenger seat, (the brown one), had had the cable cut?

This was then rejoined, and the cable repaired. Flashing glow plug light stops, yipeeee!

Vehicle comes back, all is well, pottering around town for a while. Until the engine is under load, uphill etc., then this noise, and rough gear change.

The dealer takes it back and replaces the ATF. Gear change much better, but the noise from the turbo persists.

He tells me not to drive it so hard

So I try that, and on the way back home on the M6, I cant drive it carefully enough to stop the noise.

I complain to the dealer again, he comes out and assesses, and suspects the turbo bearings are shot. Surprise surprise!!

He takes it away and says he will defiantly fix it this time.


So then, putting two and two together and, probably making five. I suspect either:

The car had the turbo issue from its last Japanese owner/dealer. Who disconnected the solenoid, then removed the glow plug bulb, to mask it.

Or the dealer/importer in the UK did this?

A strong accusation maybe, but I cant help thinking this is the case.

Either way, after 5 months of ownership, 3 of which, its been off the road. The dealer is finally taking action, so here's hoping.

Moral: Check everything before you buy, even the little things!

Thanks All

[Bob]

At least it should be sound now.

[windywatson]

At least its all going in the right direction and you should get it running as should be. With regards to the missing bulbs and cut wires, your right to suspect the reasons for it being done. Of course it was done to mask faults. I have past experiance of exactly this being done.
it begs the question, what exactly the dealer does with respect to checking roadworthiness of the vehicles he sells. I now work for a major motor home dealership as a technician. All vehicles especially second hand ones are taken out and given a thorough road test, long enough to ensure the engine is well up to temperature and hopefully discover these sort of issues.
Hope that this experience hasn't put you off ownership.

Cheers

[topbanana]

Thanks Windy, really appreciate the response.

Her is an update from the dealer,

"I have had the turbo checked by 3 mechanics they seem to think turbo is fine . Their opinion is that it is an electrical fault boosting too much power to the turbo . Had diagnostic done indicating some more sensors which are faulty "

Now funny thing, a local Bongo friendly mechanic, (not sure I can post names here?). Following a drive out in it said.

"That turbo's over boosting, and because its a VVT, it will, create that noise, when its under strain"

So here's hoping they are on the right lines.

I have to say, the dealer has been hopeless in fixing it, however I cant criticise their intent or ownership of the problem.

Thanks for the help and info, i'll keep you all updated.

Cheers

[Northern Bongolow]

the link below explains boost quite well.
it could just be a sticking or coked up waste gate valve,causing an overboost spike. a good clean out and lube may be enough.

i would check carefully around the air inlet side of the turbo, between the air filter and the turbo, any leak in the pipework may allow easy entry into the system bypassing the air filter. read the bit on boost on wiki below.

http://www.turbosmartusa.com/technical- ... explained/.


http://en.wikipedia.org/wiki/Turbocharger.