Discovery 2 TD5 Lack of Power

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Gothicsera said:
it is boosting to the correct pressure.
Click to expand...
That would be the greatest oddity i've ever seen to have good boost but not enough power ... clamp the pipe which goes to te wastegate valve and see if it goes to overboost or not cos if it doesnt means it's not boosting enough at all

...the "correct boost" which is 1.3 bar on untuned D2 involves a wastegate activity too cos if it reaches that boost without wasting some to the exhaust means that it's underfuelled if you see what i mean
 
sierrafery said:
That would be the greatest oddity i've ever seen to have good boost but not enough power ... clamp the pipe which goes to te wastegate valve and see if it goes to overboost or not cos if it doesnt means it's not boosting enough at all

...the "correct boost" which is 1.3 bar on untuned D2 involves a wastegate activity too cos if it reaches that boost without wasting some to the exhaust means that it's underfuelled if you see what i mean
Click to expand...
I'll try that tomorrow.

I say its boosting as I am seeing 215kPa MAP on the Hawkeye live data at max load
 
Gothicsera said:
I'll try that tomorrow.

I say its boosting as I am seeing 215kPa MAP on the Hawkeye live data at max load
Click to expand...
You said that before i recommended to tighten the wastegate which you said you did so if it doesnt go above that value means it's low, you can calculate the boost exactly by extracting the AAP from MAP(boost = MAP - AAP knowing that 100Kpa = 1 bar) but usually the AAP is around 100 so you should see MAP around 230 at full load but for that the wastegate must be open which means the boost of the engine is higher(a well fuelled untuned Td5 should peak up to 1.7 bar unrestricted by the ECU)
 
I did tighten the wastegate 2 turns. Checked boost again this morning, still 215kPa.

Checked injector clearances, all were correct

Finished replacing the intercooler hoses all originals were OK and not delaminated. Steel pipe in good condition, looks like it was recently replaced.

Clamped off wastegate hose and get over boost at about 240kPa

Re-ran the stall test this morning - 2400rpm, so marginally better than the last result.
 
Gothicsera said:
I did tighten the wastegate 2 turns. Checked boost again this morning, still 215kPa.
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still low then... try to tighten the rod untill you get 230 MAP but IMO you should replace the wastegate actuator (THIS) and make sure that the turbo's wastegate spigot is not sticking and there is no leak at the exhaust manifold cos it should have been more boost with the rod tightened... in ideal conditions it is rising with around 7-8 Kpa / thread so if it was OK you should have got at least 230 after the adjustment as IIRC it was 215 before too
Gothicsera said:
Clamped off wastegate hose and get over boost at about 240kPa
Click to expand...
now it's certain that the engine is boosting enough cos the overboost limit is ar 1.42 bar so if it kicked in at 240 MAP the AAP was 98 and the engine boosted more... so now all you must do is to make it reach at least 230 MAP at full load but 235 is even better and then the stall test should pass well too
 
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sierrafery said:
still low then... try to tighten the rod untill you get 230 MAP but IMO you should replace the wastegate actuator (THIS) and make sure that the turbo's wastegate spigot is not sticking and there is no leak at the exhaust manifold cos it should have been more boost with the rod tightened... in ideal conditions it is rising with around 7-8 Kpa / thread so if it was OK you should have got at least 230 after the adjustment as IIRC it was 215 before too

now it's certain that the engine is boosting enough cos the overboost limit is ar 1.42 bar so if it kicked in at 240 MAP the AAP was 98 and the engine boosted more... so now all you must do is to make it reach at least 230 MAP at full load but 235 is even better and then the stall test should pass well too
Click to expand...
I just tightened it another 1.5 turns. Now 9 threads showing and still only see 215kPa.

Connecting the wastegate directly to the boost hose, bypassing the modulator, I only get 208kPa with the same wastegate setting.

No visible signs of leaks at the exhaust manifold (sooting).

Going to try and get the heat shield off the turbo to see if i can get at the wastegate actuator.
 
As it went to overboost with clamped wastegate hose but no improvement no matter how you tighten the rod means that the actuator's spring might be weak and it opens fully at around 1.10 bar.... better replace it
 
I'm close to giving up with this now.

Swapped on the new wastegate actuator. Even with it wound right in max MAP was 180kPa, so that was a waste of money.

With the original fitted max MAP is back to 215-220 with 10 threads showing.

Tightened it up to 5 threads showing and got over boost, backed it off a turn.

Still down on power though, stall test not improved.

Im going to get a complete used turbo and swap that. If that doesn't sort it, then I'm done with it. It'll just stay as it is.
 
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Gothicsera said:
I'm close to giving up with this now.

Swapped on the new wastegate actuator. Even with it wound right in max MAP was 180kPa, so that was a waste of money.

With the original fitted max MAP is back to 215-220 with 10 threads showing.

Tightened it up to 5 threads showing and got over boost, backed it off a turn.

Still down on power though, stall test not improved.

Im going to get a complete used turbo and swap that. If that doesn't sort it, then I'm done with it. It'll just stay as it is.
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So sorry to hear that you are still having trouble with this.
I am not sure if you want to do this but you can get a new turbo rebuild kit.
Lots of them here and threads on people's experiences with them.
Maybe a VVT kit?
 
Gothicsera said:
Going to try and get the heat shield off the turbo to see if i can get at the wastegate actuator.
Click to expand...
Getting it off is relatively easy, putting the bolt in that you have to tighten at the rear is a bit of a PITA.

Still not understanding this. It would seem you do have boost according to all the tests you have done, yet not got actual power.

But the low stall test tends to point to a failing torque converter.
Maybe a rethink on the latter?
Maybe a change of ATF and filter in the auto box? Just to start with?
 
Stanleysteamer said:
So sorry to hear that you are still having trouble with this.
I am not sure if you want to do this but you can get a new turbo rebuild kit.
Lots of them here and threads on people's experiences with them.
Maybe a VVT kit?
Click to expand...
If i was certain a different turbo would fix it then I'd splash a bit more cash.

But frankly I'm 100s of quid and 4 solid days into chasing my tail with it now and ultimately I need to decide what to do with it and how much more to throw at it.

I think sierrafery mentioned about exhaust restriction. I'm going to pull the centre section at some point and make sure that's not clogged or fallen apart inside and causing a restriction. It looks ok from the outside, but that could mean nothing.

Aside from a different turbo, injectors and exhaust everything else has been changed with no significant difference to performance.

Or perhaps the engine is just knackered.
 
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Stanleysteamer said:
Getting it off is relatively easy, putting the bolt in that you have to tighten at the rear is a bit of a PITA.

Still not understanding this. It would seem you do have boost according to all the tests you have done, yet not got actual power.

But the low stall test tends to point to a failing torque converter.
Maybe a rethink on the latter?
Maybe a change of ATF and filter in the auto box? Just to start with?
Click to expand...
Yes but to get the boost I had to wind the wastgate actuator in way more than I should. Limiting the amount the wastegate opens quite a lot more than is normal to get the same level of boost, or gas flowing through the turbine side with less being bypassed. To me that points to issues there somewhere.

Changing the gearbox oil is on my list of jobs to do.
 
Gothicsera said:
If i was certain a different turbo would fix it then I'd splash a bit more cash.
Click to expand...
I must insist, as long as it goes to overboost IMO it's not the turbo, tigthen the wastegate until overboost then one thread back at a time untill it doesnt then it should go to around 1.35 bar boost...
1. did you check the injector's roughness with hawkeye?
2. is the original ECU fitted to the vehicle? if you dont know tell me the p/n from it's label, it should be MSBxxxxxx if it's Eu2 engine
 
sierrafery said:
I must insist, as long as it goes to overboost IMO it's not the turbo, tigthen the wastegate until overboost then one thread back at a time untill it doesnt then it should go to around 1.35 bar boost...
1. did you check the injector's roughness with hawkeye?
2. is the original ECU fitted to the vehicle? if you dont know tell me the p/n from it's label, it should be MSBxxxxxx if it's Eu2 engine
Click to expand...
I have it running up to 230kPa MAP/130kPa boost, with 5 threads showing on the wastegate.

I'll check the roughness again tomorrow but remember seeing 2-3rpm on each cylinder when I scrolled through yesterday.

I'll grab the ECU number tomorrow, but I do know it starts MSB
 
Gothicsera said:
I have it running up to 230kPa MAP/130kPa boost
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and with that value you still get low power result on the stall test? .... and confirm whne you checked the injector adjustments did you undo the adjuster screw as when the rocker arm was at full stroke the injector's plunger was loose then tightened untill the plunger bottomed out then one turn back?
 
sierrafery said:
and with that value you still get low power result on the stall test? .... and confirm whne you checked the injector adjustments did you undo the adjuster screw as when the rocker arm was at full stroke the injector's plunger was loose then tightened untill the plunger bottomed out then one turn back?
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Yes, stall test still 2200-2300rpm.

And can confirm injector clearances set as suggested.
 
Gothicsera said:
Yes, stall test still 2200-2300rpm.

And can confirm injector clearances set as suggested.
Click to expand...
Very strange, i must admit that i'm running out of ideas, it's very strange to be low power at normal boost even if for that boost more throttle than normal is needed.... what's the air flow and IAT reading at full boost
 
sierrafery said:
Very strange, i must admit that i'm running out of ideas, it's very strange to be low power at normal boost even if for that boost more throttle than normal is needed.... what's the air flow and IAT reading at full boost
Click to expand...
Do you not think, at all, that the stall test indicates a problem with the torque convertor? As that is the normal received wisdom.
You too seem to think it isn't the turbo.
 
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