Am I in limp home mode?

1999 TD5 defender 110,
I was driving on the motorway, up hill about 70mph with quite a lot of heavy stuff on board, sudden power loss and speed went down to 50, pulled over and had a quick look but couldnt see anything abviouse. Car starts ok and ticks over fine, and seems not too bad up to 50, if I stay at 50 it drives ok, if I accelerate it suddenly cuts power and drops down to around 50, changed the fuel filter as I found one in a local motorfactors (we were on our way to scotland) but the car was the same on the return journey even when empty.
I've had a trawl through and will check
1: MAP sensor
2: MAF sensor
3: Turbo pipes (can these suddenly delaminate?)

anything else I should look at

waste gate or oil in loom /ecu

sounds like turbo overboost. If you turn it off and back on again does full power return until the next time it happens?

yes it seems to go ok untill I take it over 60, I'll check the waste gate rod thingy as well.

7tastic said:

yes it seems to go ok untill I take it over 60, I'll check the waste gate rod thingy as well.

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Same problem with mine - lots of wd40 a pair of mole grips on the bar and a fair bit of force and it freed up. Takes a fair bit of force towards the rear to move it but it all good now.

put some pliers on the hinge to the rod and it wasn't that stiff (couldn't move it gripping the rod) wd40 and a bit of wiggling and it felt a bit less stiff. Noticed the whistle from the turbo when I started and felt a lot quicker, reved a lot faster so hopefully that was it, I'll take it on a run on the m25 tomorrow to see.
I'll clean the MAP sensor as well just to make sure.
Wish I had the internet whilst I was in Scotland, if this does cure it I could have easily have sorted it for the run home.

No...still got the same fault, feels realy strong up to 70 then feels like the power is lost and drops down to 50 quite quicky.
cleaned MAP sensor, MAF looked ok, no oil at eather end of loom, looked down pipes and they seemed OK
the waste gate rod moves smoothly, how hard should it be to move? I put a spanner on the linkage and it was quite easy to move.

Any more ideas?

7tastic said:

No...still got the same fault, feels realy strong up to 70 then feels like the power is lost and drops down to 50 quite quicky.
cleaned MAP sensor, MAF looked ok, no oil at eather end of loom, looked down pipes and they seemed OK
the waste gate rod moves smoothly, how hard should it be to move? I put a spanner on the linkage and it was quite easy to move.

Any more ideas?

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Is it like you hit a brick wall and suddenly feel the power go rather than a gradual thing?

Not quite a brick wall but instant power loss until it gets down to 50, a bit scary if you are halfway past a lorry then need to slot back behind it. If I try and go faster it feels like the throttle isn't doing anything, if I ease off a bit then I can get up to 60 by easing the throttle down gently but as soon as I go faster it happens again. It will accelerate up to 70 quite strongly with plenty of turbo feeling (if you see what I mean.)
No noticeable smoke out the back.

I'm going to replace the small 8mm pipes as I think one of them operates the waste gate, other than that I'm stumped and will have to take it to a garage unless there's something else i can check?

If you know anyone having a Nanocom .. Borrow it. Take it for a spin and read the turbo pressure at the point of going into limp mode. As mentioned by others, it could be a turbo pressure issue. Could also be a turbo hose jubilee clip which is not tight or broken. This may cause you to loose turbo pressure..

Have you checked the earth cables? Sounds like a very similar thing that happened to mine back in Jan. Auto sparks put it down to dodgy earth cables, fitted two new ones. Solved the problem.


Though mine is now going into limp mode totally randomly mainly at town speeds 20 - 30mph. Trying to find a Nanocom too..

I now think its not going into limp home mode is it recovers without having to turn off and restart (is this correct?). I got someone to follow me and i do get black smoke when the power loss happens. I ordered some new intercooler hoses but one they sent was incorrect so I've got 2 shiney ones and one manky one on at the moment. Just my luck that the one that was wrong was in the worse condition and looked like it had been repaired before (though I couldnt see any splits or holes). A replacement should be here next week as all their kits were wrong.
Next to check will be the intercooler, can I fill with water and see if any leakes? or is there a better way?

You can only recover from limp-mode with a re-start. Black smoke = over-fueling or too little air. I guess you miss air.

Did you check the jubilee clips? and what do you mean by 'worse condition' and 'manky' ?

... and did you follow the other recommendations before buying new parts?

and here is me thinking limp mode was something you had when you drank to much Guinness

Buckhandle said:

You can only recover from limp-mode with a re-start. Black smoke = over-fueling or too little air. I guess you miss air.

Did you check the jubilee clips? and what do you mean by 'worse condition' and 'manky' ?

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The one pipe that was missing from the Kit was the one with a repair on it so I had to put the old one back on for now. The pipe itself was quite soft and squashy with a few indentations, especially where the jubilee clips sit.
and yes I've checked the following
waste gate actuator moves OK
No Oil in red plug or at cylinder head end
replaced small hose to waste gate
new fuel filter.
new air filter
cleaned MAP with carb cleaner
Unplugged the MAF and it did the same

and it seems I'm not in Limp Home Mode as it recovers by just slowing down a bit.

and here is me thinking limp mode was something you had when you drank to much Guinness

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I have this problem too

Clean and tighten the main ECU earth. It can cause all sorts of intermittent and apparently unrelated problems if corroded.

Thanks Shifty I'll check it out, any pointers on where it is or is it obviouse when I have a look?

7tastic said:

Thanks Shifty I'll check it out, any pointers on where it is or is it obviouse when I have a look?

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Main ECU earth on a TD5 Defender is in the cubby box under the drivers seat. You should be able to see it quite easily. Take it all apart and clean everything back to bare metal. Put it all back together with a good smear of petroleum jelly or copper grease.