Help Poor running

[mickhayward]

Can anyone point me in the right direction. I have a 94 2.7 TD. It has a general lack of power with no turbo surge as it had before. Worst of all this is coupled with periods of extreme loss of power together with a loud rattling noise from the engine. At this point large plumes of smoke emerge from the exhaust (blue) Some times this clears but the general lack of power persists. I thought it might be the turbo. Have removed hose coupling turbo to inlet. There seems to be a pressure generated at higher revs. Have no idea what it should be like though. I would welcome any comments.

Thanks Mick

 

[supertaff]

Check your waste gate valve. On the right hand side of the engine, as you look at it from the front, you will see a heat-shield with a rod going to a lever under the heat shield. There are 3 x10mm bolts holding the heat shield - Undo these and remove the heat shield. With the engine switched off, see if you can move the rod back & forth slightly - If it wont move at all , your waste gate valve has seized(quite common occurence). spray plenty of WD40 around where the lever at the end of the rod goes into the block, and gently try to move the rod back & forth. You may need to use a mole-grip or fit a spanner on the end of the lever to give yourself a bit more leverage.
The rattling noise you could hear is the Turbo pressure relief valve ( on inlet manifold towards back left hand side of engine) activating - because waste gate valve not working.
Depending on which position it seizes, it can give the effect of an "Exhaust brake" as on Lorries & coaches.
Matt.

 

[Boggert]

Tend to agree, my mates Landie suffered the from the same thing, I put it down to a Landie being a landie, he then changed a split turbo pipe and it went like a rocket.

 

[mickhayward]

Hi Matt

Thanks for this. Removed shield and tried waste gate. It moved without any effort. However running the engine at any speed failed to get it to move. Is this normal? The lever is at rest is towards the front of the car. Could it be the vacuum actuator mechanism? I'm clutching at straws here

Cheers Mick

 

[supertaff]

Could be a faulty vacuum actuator . I think you are in the right general direction. You can check to see if it's the actuator by giving it some hefty revs. ( about 3,300 to 3,500 rpm ) . If the actuator doesn't move the rod,
this could be the problem. I think we are looking in the right area.
Does the clattering noise start at just over 3,000 rpm ? Have a look at the turbo pressure relief valve ( dome shaped thing) on the back of the inlet manifold on left side of engine. Don't worry if it looks like oil leaking from it, as this is normal when it is activated. But the fact that it has activated suggests a problem around turbo, so check if actuator is moving the rod operating waste gate valve.
Matt.

 

[mickhayward]

Hi Matt

Had engine flat out with no movement of the rod or wastegate valve
I'm of course assuming the turbo is producing some huff. If as you say the pressure relieve valve is working then I suppose it must be. Took it for a run not so long ago. Initially it wrent okay but stlll with low power. One mile later rattling started and remains as the power and speed decreases. Small pipe to acctuator seems okay so I think the next move is to try a new accuator. I suppose I can check it by applying air pressure to the small hose to see if I can get the acctuator to move.

Mick

 

[Toolbox]

I doubt by stationary revving of the engine you will ever see the waste gate rod move.
It only opens to dump excess pressure at full boost pressure from the turbo.

I would have a look in the downloads and do the EGR mod before you condemn anything.

 

[supertaff]

Hi Jeremy, if you remember, I had the same problem on my Mistral, the pressure release valve clattering at just over 3,000rpm, she was down on power to what she is now, and it turned out to be the waste gate valve seized. With him mentioning the "clattering" noise , I thought it would be the turbo pressure release valve activating, pointing to the waste gate valve not operating. There must be turbo pressure for the turbo pressure release valve to activate.
Matt.

 

[Toolbox]

Hello Matt,
Yes I do remember your problem and they do sound very similar symptoms to Mick’s, it’s the low power at low revs that is a bit weird, if the turbo was working ok and only blowing the safety valve on the manifold at high revs / load, due to much boost, then it should be ok on power up to the point the safety vent opens, unless this is partially open at a lower boost pressure and the really blows of under high boost.

 

[mickhayward]

I can't understand Jeremy's comment on the turbo not working when the car is stationary and the engine running flat out therefore not opening the waste gate.
Are you saying it's dependent on road speed. I don't think so.

Mick

 

[mickhayward]

Hi All,

looks like Jeremy's suggestion has proved fruitful. I clamped off the pipe feeding the EGR valve with a small pair of mole grips and hey presto an instant change to the running caracteristics. Took the Maverick for a run (with the mole grips safely secured with cable ties) and found that all of the symptoms have disappeared. I went straight home and fitted a ball bearing in the tube. Thanks to Shark1e. It seems even better. Only problem now seems to be a reluctanve to reach max revs in low gears but to be honest my wife drives it a lot more than I and it probably never goes over 2500 rpm. Looks like its time for a good thrash down the moterway, this usually does the trick.

The question now is how do I remove the offending EGR valve.

Thanks to lifesavers Matt and Jeremy for your time and comments.

 

[supertaff]

Glad you managed to sort it out. I don't know of anyone who has actually taken the EGR valve off as the blanking method is safe enough. If you do manage to remove it, I'm sure a write-up in the workshop downloads would be worth a mention.
All the best, Matt.

 

[mickhayward]

Thanks Matt

I'll see how it goes. May be best to leave well alone now its running okay.

However, If I do suceed I,ll put it on the web.

Thanks again for your help

Mick

 

[mav]

Are our members good or what!.

What better could we wish for than what we have in our present members, Nothing s to much trouble.

Well done to you Toolbox, Matt, Shark1e and others.

Mav.

 

[MikeP]

Lack of POWER

Hi to all

And thanks guys
I have just joined the club and already it is paying off! I have a similar problem with my Terrano 2.7TD, Loses power, however when I switch the engine off and restart, its ok again. This happens quite a bit. I have read your comments and think that you may have solved my problem,will let you know.

 

[supertaff]

Welcome aboard Mike, You will find that most of the members will try and help sort any problems with your vehicle. There is loads of info. in the Workshop downloads, and if you search previous threads, pretty much every problem that can occur has been covered.

All the best, Matt.