My recently acquired 307 lacks power. Everything happens in the first half inch or so of accelerator pedal movement. Pressing it beyond that has little effect.
The local garage has just changed the timing belt at 95000 miles. I had them check for fault codes but they found nothing wrong. They reckon that the turbo isn't spinning and advised me to take it to a Peugeot dealer, something I'm reluctant to do, given the way they charge!
I've checked the air flow sensor which is working normally. Are there any other sensors I should look at before biting the bullet?
{and the year is? - now added}
Edited by Dynamic Dave on 04/04/2008 at 19:53
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My apologies, the year is 2005 (53 plate)
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the year is 2005 (53 plate)
That would make it a 54, 05 or 55 plate.
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I've checked the air flow sensor which is working normally. Are there any other sensors?
One or two.... dozen.
I'm intrigued to know how you checked the MAF was in spec? Does this one have a FAP in the exhaust? What's the letter after "RH" in the VIN number?
While they were checking the codes; why didn't they check the 1800 lines of live-data available for things like fuel and boost pressure?
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Sorry again, can't type! It was first registered August 2003.
I checked the MAF by piercing the signal wire with a pin and measuring the voltage with respect to earth. I got the specifications from
tinyurl.com/565wtj
I believe it has an FAP, The Haynes manual says the FAP is fitted to the HDi 110.
The letter after RH is S.
I've no idea why they didn't test any further than looking for fault codes. Probably because I didn't specifically ask them to.
Thanks,
Richard
That has to be a record a 179 character URL shrunk to a incredible 25 through the magic of TinyURL site - see link in Discussion
Edited by Pugugly on 04/04/2008 at 18:05
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Richard
The RHS has indeed got a FAP; the RHZ 110hp and RHY 90 hasn't; the RHR 136hp has.
Check pin 3 of the MAP sensor; it should be around 2.4 volts atmospheric and c.4 volts at full boost - or put a pressure gauge on it.
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Thanks for that. Where do I find the MAP sensor? Is it the one on top of the intercooler?
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Yes; that's the one.
As you seem to be a member of that site; maybe they'll have full instructions.
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Once again, thanks for that info.
I'm not a member, I just stumbled on it a couple of days ago when looking for info on the sensors. The trouble is there's only the one page on that site. I can't find the rest of the article.
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Ahh; so that's why. I thought we were all using your paid access or summat.
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Just measured the signal from the MAP sensor. It sits at 2.34 volts with the engine stopped, rising to 2.5 at 3500 RPM.
That figure is just revving the engine in neutral. Would you expect anything different under load?
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The saga continues.
I've tested the MAP sensor on the road. It does much the same, i.e. the reading at tickover or with the engine stopped is 2.34 volts. The highest reading I got was 2.6 volts at about 3500 RPM pulling uphill in second gear. Fairly good news I suppose. because it shows that the turbo is at least doing something. I reckon that if it was broken I'd see if anything a vacuum at the intercooler.
On the downside though, the antipollution fault has just come up. Do you think that's been the trouble all along?
Thanks
Richard
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Richard
The graph for that MAP shows exactly that voltage at atmospheric - BUT - it should reach 3 volts at 1.4 bar and 4 volts at 2 bar.
Looks like you've got serious underboost or a duff MAP. Check everywhere for a boost leak - including the EGR valve. See if you can put a gauge on it.
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Before I start, thanks screwloose for all the info.
It's starting to make sense. I've measured the boost pressure in the hose from the intercooler to the inlet manifold. The highest pressure measures is about 2.5 psi or 0.16 bar which corresponds to about 2.6 volts. Also, the MAP sensor reading drops to 2.25 on overrun, suggesting a vacuum in the inlet, which is what you'd expect if the turbo stops blowing. All this suggests to me that the MAP sensor is probably OK.
Wouldn't a boost leak be audible? There's whooshing sound or anything like that. I hired a van once with a split turbo hose and that made a horrible noise.
All this suggests something wrong with whatever controls the turbo? Is there a solenoid valve or something that controls the waste gate? Perhaps the waste gate is stuck open.
Where do I find the EGR valve?
By the way, the antipollution fault has mysteriously gone away.
Sorry if these questions show my ignorance. I've never had a turbo diesel before.
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Surprisingly enough; the bigger the leak the less noise it makes. A loose clip allows quite a pressure to build before it whistles out - a split hose doesn't. Look for oil mist.
The anti-pollution warning is a generic one that just means there's a code - think of it as the equivalent of a MIL light. It would be nice to know what codes are there.
The turbo; intake valve and EGR control solenoids are all down the front of the engine - gearbox end. This has got an ECU-controlled VNT vane-type turbo, so it's actuator could be stuck shut. Follow the hoses to find out which one does what.
2.25 volts is 0.85 bar. Seems to read fine in that range.
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I've found three similar solenoid valves in front of the engine.
Two are mounted on a bracket. The right hand one is directly in line with the thermostat housing, the second is about 4 inches to the left and slightly lower. The third valve is further to the left, lower still and seems to be mounted on the engine block.
They all have tubes attached that as far as I can see come from the vacuum pump.
Am I on the right lines? If so which valve is which? I assume that the turbo valve is the most likely culprit.
Thanks again,
Richard
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Richard
There's only one way to tell for sure and that's to follow the vac hoses leading away.
GM use a similar cluster on the Vectra - and I've lost count of the number of times I've seen the hoses have been put back on the wrong solenoid.
They share a vacuum feed from the pump; there are 2 EGR and one turbo actuator.
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Thanks again, screwloose.
Just a quick thought.
Once I've located the turbo control valve, if I were to take the two vacuum hoses off and join them together wouldn't that tell me if the problem is with the valve or the actuator? If the turbo comes to life then the problem would be with the valve, otherwise it would be with the actuator, or even both.
Would that be a silly thing to try?
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Yes it will certainly prove something.
The turbo will go to idiot-boost and blow the hoses and intercooler apart before limp-home can stop it - or maybe no boost at all.
Not a test that I've ever dared try - let me know what happens.
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It wouldn't do much at tickover though would it? I'm tempted to try it!
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True; there shouldn't be any boost at tickover - even a direct-acting wastegate is fully open then.
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Just to let you know, it's all working OK now.
It turned out, as we suspected, to be the turbo boost vacuum valve. Also there was a split elbow on the turbo actuator.
Once again, thanks screwloose for all your help.
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Result! Nice going; there's not many people that have won against an HDi. Easy they ain't!
Most garages would have fitted a turbo and an ECU by now and would still be clueless.
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i have the same i think the turbo is spining as when i rev the engine and turn it off strait away you can hear it spining down,
can someone take a look at the pic below and tell me if its normal
img374.imageshack.us/img374/4610/307pipepn2.jpg
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Max
[This would have been better as a new thread.]
That's a fairly normal-looking dozer valve?
What engine does yours have and what's the exact problem - all the details.
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