BX TURBO

bernie · Unread post by **bernie** » 28 Jul 2003, 01:01

Is there a way of telling if the turbo is working as mine has lost it's turbo push[V][:(][V]?
Any idea of the cost of a turbo?
Bernie
BX 17TZD Turbo 1992
BX 19D Meteor Est. 1991

jeremy · Unread post by **jeremy** » 28 Jul 2003, 14:42

Why not disconnect the turbo feed to the intercooler (easy on mine - may be more difficult with another turbo) rev the engine a bit and see if loads of air comes out. Dont go beserk with the revving - after all the thing begins to pump hard at about 2000 revs.
From reading this and other boards turbo troubles are very rare. have a good look at the pipe leading from the intercooler to the pump and to the warning light switch under the battery. Mine split on the warning light switch - the sort of repair I like - cut off the end of the pipe and refit!
Jeremy
Jeremy

bernie · Unread post by **bernie** » 28 Jul 2003, 20:05

Yes there is air forced out from the pipe but not knowing how much pressure is normal.It was also fairly hot air.
One thing I did notice, the noise from the pipe was almost like the exhaust blowing. Is this normal? Or has the turbo got an internal leak from the exhaust side?
Any idea about the waste gate stuck? can I get to it?
I take it you are the same Jeremy from the http://members4.boardhost.com/citroen_bx/msg/34497.html
forum?
Bernie

Guru Meditation · Unread post by **Guru Meditation** » 28 Jul 2003, 21:09

Hot air is normal and a lot of noise would be normal too after all the turbo is fed directly off the exhaust. Best way to check turbo function is connect it all up like it should be and get a boost gauge on it should be about 1 bar max.
Guru Meditation
btw installing a boost gauge means splicing in a t-piece off the boost sensing pipe to the fuel pump, I think.

rory_perrett · Unread post by **rory_perrett** » 28 Jul 2003, 21:16

Bernie
I may be way off the mark here but lack of oomph in my TZD turned out to be that old favourite a broken accelerator pedal bracket - check you are getting full throttle at the pump. A new fuel filter did wonders as well for performance when I finally got round to changing it after 150,000+ miles
Rory

bernie · Unread post by **bernie** » 28 Jul 2003, 22:11

Rory
Yes I've checked the throttle action and unfortunatly it was ok[:(]
Guru
Thanks for the info, I'm going to try a boost gauge next

bernie · Unread post by **bernie** » 29 Jul 2003, 01:02

I've got 0.2 bar at 2000 rpm and
0.5 bar at 4000 rpm.
So what's the verdict?

Jonesy · Unread post by **Jonesy** » 29 Jul 2003, 01:52

Bernie
If you are only getting between 0.2 and 0.5 bar, then you are not getting enough boost. Thats only about 3-7.5 psi. Don't know quite how much boost you should get, but its more than your reading.

Dave Burns · Unread post by **Dave Burns** » 29 Jul 2003, 02:31

Looking like a prob. with the turbo waste gate, could be stuck or even worse burnt and corroded.
One of two makes are usualy fitted, Garret or KKK, one has a remote wastegate actuator (can't remember which) and the other's is integral.
The remote one is easey to deal with, you can tell if its stuck by trying to move the pushrod, just remember its up against healthy spring pressure.
If its seems ok the actual gate could be shot, don't know if this is a common occurence on turbo's but its not beyond the realms of possibility.
Dave

Unread post by **RichardW** » 29 Jul 2003, 13:07

Bernie,
You should be seeing around 0.8 - 0.9 bar once the turbo is on full 'blow'. I think one of the guys who runs a tuned BX TD reports seeing some boost 'creep' at high revs. How did you measure the boost pressure? You need to measure it under full load conditions, eg foot to the floor, 3,500 rpm with a good load on the engine - like climbing a big hill [:D].
If you are sure the turbo is shot, it will have to come off, as there is bugger all access to it.... You might get it off with the head in-situ, but it is not easy. When I changed the head gasket on my TD I had to remove the manifolds to get the head bolts out, and found it difficult even on the bench (the stupid socket cap screw in the centre of the inlet manifold was very stubbon - I had to remove the turbo and exhaust manifold first then get the bolt out with a pair of stilsons). Of course it is not possible to do this with the head in the car as there is no room to get to the fixings, and no where to get the exhaust manifold out!
Richard

Gavin1 · Unread post by **Gavin1** » 29 Jul 2003, 14:57

I had a similar problem on my previous bx a gradual loss of power but with no symtons of anything being wrong - various poeple told me the turbo was shot etc. However the car had a Lucas CAV fuel pump and it was the fuel / boost controller on top of the fuel pump that was the problem. Overtime it had got clogged up with oil etc from the feed from the intercooler and even though the boost was there the pump wasn't increasing the amount of fuel being injected.
I took my boost sensor apart and cleaned it and put it back together and it solved the problem.
If you're not brave enough to take the boost / fuel adjuster apart then maybe getting the checked at a diesel tuning specialist may help.

jeremy · Unread post by **jeremy** » 29 Jul 2003, 19:12

I think there is a lot in what Gavin is saying.
The turbocharger is driven from the exhaust gas and as we all know with these engines it takes a little while until full boost is attained - ie up a long hill the thing gets faster and faster the longer it is under load.
The extra fuel device is I'm sure progressive in action and the greater the boost the greater its fuel delivery. The greater the fuel delivery the greater the volume of exhaust gas, and the greater the power available for the turbo, hence the greater the boost pressure.
The boost pressure you have quoted would seem a bit low if properly measured - as suggested somewhere - on a long hill at about 3500 revs. If insufficient fuel is reaching the engine under boost conditions then there won't be enough exhaust gas to drive the turbo at full power and boost will suffer.
You may already have mentioned it in which case I apologise - but have you checked the fuel and air filters? problems with either would hinder the proper operation of the turbo.
Another common fuel problem it would seem is air in the fuel. It seems that if you have a Roto Diesel pump this is probably accompanied by uneven running and possibly mysterious speeding of the engine but the Bosch doesn't have this problem. Often the first sign is bad starting but I suppose air could be drawn in at other times. I mention this as i changed my fuel filter yesterday for the first time and was surprised that while the input and output pipes were fixed with a banjo bolt, copper washer etc, the pipe itself was simply pushed about 1 1/2 inches into a rubber tube for the inlet and a similar arrangement for the outlet which has acquired a jubilee clip. After reading tales of air in the fuel I have now put a clip on the inlet.
Jeremy

bernie · Unread post by **bernie** » 29 Jul 2003, 19:40

Jeremy
Yes it is a Roto, I'll check the over fuelling device.
As to air input, it starts and runs perfectly ( it will red line with ease on the road) except THAT certain push
The first thing I checked was the filters.
As to the test it was stationary with NO load

jeremy · Unread post by **jeremy** » 29 Jul 2003, 20:55

Bernie
I'm absolutely sure your test must be under load. I seem to remember a thread on Boardhost which has probably gone now where someone fitted a boost gauge and had readings similar to yours but was surprised to find he didn't get any vacuum - but thats another story.
So far as I know the correct reading is max between 0.8 and 0.9 bar (10-12psi) and much over that should set off the overpressure light. I would have thought .5 bar without load wasn't bad.
I was going to suggest that you checked the small outlet from the intercooler was clear by putting a small twist drill (hand held) into it and twisting it to draw out any accumulated muck but if you're getting 0.5 bar its probably ok. Still worth ago I suppose.
I didn't realise the extra fuel device was serviceable but its probably worth a go as well as its easier than the turbo.
Can you get your boost gauge in the car so that you can try it under load? from the sound of things (and the apparent reliability of turbos) I'd try everything before it.
Jeremy

thatorangething · Unread post by **thatorangething** » 30 Jul 2003, 00:36

Assuming of course that air filter is OK, and all the hoses are on, EVERY one of these that i have ever had in my workshop with this problem has had a rotodiesel pump with a burst diaphragm on the boost/fuel device. Buy a diaphragm from a diesel specialist and change it - very very carefully! the car needs the additional fuel to make the turbo boost fully. have never had a turbo fail yet on a BX. Changing the subject completely, have been doing a pull type clutch on a 2.0 16V Xantia today, what a hateful pig of an installation, who the hell dreamed that one up!!!!!