Over boosting problems?

[Wreckless]

Being new to this forum lark, I'm not sure whether I'm going about asking my question in the right way but here goes:

Being a non-mechanic member, and before once again throwing myself, and my ever-shrinking wallet, to the mercy of my local Nissan dealership, may I enquire whether any member(s) can enlighten me on a problem with my Patrol, so that at least when I go to their garage I have some idea of when they are feeding me a load of crap (again) :banghead

Originally a seemingly intermittent fault, has now grown to a fully blown crisis. Initially the fault showed up as loss of power, after prolonged driving, when climbing steep inclined roads at speed. ‘Remedied ‘ by lifting off the throttle momentarily, then re-accelerating. A number of Nissan garages, given the opportunity to identify and cure the problem, variously claimed to have sorted it (and charged me accordingly) only for it to re-occur next time I returned to the hills of Ireland (there not being too many such hills around Milton Keynes/S.E England, my normal driving area, so difficult for garages to replicate the fault). The ‘intermittent’ fault has recently become significantly worse. After (say) 1-2 hrs driving, and everything nice and hot, the engine management light comes on, and engine switches to ‘get-home-safe’ mode, similar to driving Trabant instead of 3L patrol Turbo diesel.

Wanting to avoid getting taken for another ride, I took the Patrol to a well-recommended diesel specialist. He found that the initial loss of power was due to a split intercooler, but that this was caused by the fundamental problem – the engine is over boosting. Sadly for me (and my wallet again), while they have identified the problem, and identified what is NOT causing the over boosting,(Work Sheet reads: remove and repair intercooler, found EGR gaskets blowing, have pipes refaced, replace gaskets, read codes, found over boosting fault, change control valve – no change. Check turbo rod movement against vacuum, monitor vacuum control to control valve when driving, not pulling waist gate back, check and change boost pressure sensor, substitute air flow and boost sensor from donor vehicle – no change) they cannot positively identify the real cause. The prime suspects are the turbo itself (although they strongly feel that the turbo is not the cause) or the ECU. Not having the Nissan software they are unable to re-programme the existing ECU and would not be able to programme a new one if that option was taken. They feel that I have to go back to a Nissan garage for checking of the ECU :-(( I can just see their cash register smiling when I roll up………

Do any of these symptoms ring any bells with you guys? Having already spent quite some money on trying, unsuccessfully, to solve my Patrol’s problem, I would just like to know that I am not actually looking into a bottomless pit of repair expenses and that there is a solution out there !! :nenau

 

[davemud]

Hi Wreckless

what patrol do you have would be worth adding your motors details to your profile
do this under userCP then edit signature

thanks davemud

 

[Deleted Member D]

Weak Trol power

Hey up bud.
From what I can gather from your txt you own a mighty Y61 3.0TDI ?
Not sure bout the age tho mate

but I bet its a 98 to 03 model ?

If it was your intercooler you would more than likely have heard it especially with acceleration. (sounds cool but aint). Or if your cooler pipes split or loose would give nice black smoke trial and/or some nice turbo hissing type noise.

Turbo boost can be dropped a little if necessary but acquire and fit turbo boost gauge first to keep an eye on pressure.
EGR valve can be blocked too. Common with TDI owners.
Air Flow Meter could be a possible fault too.
Take it to a Nissan clinic and get them to plug it in to find faults and they may be able to pin point your problem.
However have a good look on
http://www.patrol4x4.com/forum/index.php too. Thez alot of very good info on there for Patrols of all ages and types.

 

[extreme-4x4]

ok im no mechanic, but is the valve that opens the turbo controlled by engine pressure (oil pressure) so we could be looking at blocked breather or kinked blocked small hose to the turbo valve.

 

[Wreckless]

Tks Davemud. I have amended my signature (I did say that I am new to this game).

I found an interesting article referred to in an old post http://patrol4x4.com/forum/showpost....1&postcount=12

At least I could recognise my Patrol's symptoms. The diesel specialist that I had been recommended to use is SMS Diesel Services nr Buckingham. They have struggled manfully to resolve the problem. At least (unlike 2xNissan dealerships and 1x independent previously) they identified over boost as the core problem. Having isolated the components that are NOT causing the over boost they believe the problem rests with the ECU and they cannot sort that and so have to refer me back to Nissan. However, this article has another approach it seems.

Straw clutching on my part?

 

[davemud]

Has any one put a boot gauge in line to test for boost pressure at all. that's the only way you can confirm over boost.

Have you disconnected the battery for an extended period 2/3 hrs. or over night to reset ecu settings.

Have they or you can checked the correct pipes go to the turbo control solenoid valve that should be locked just near the air box by the rad,
you follow the vacuum tube of the turbo actuator back to the control solenoid valve it should meet up with the valve in the middle of the three ports one port tube goes in to the air box the other goes to the vacuum source.

Have you got a copy of the electronic workshop manual page EC-1261

 

[Wreckless]

Hi again Davemud. Sorry for not getting back but been away. Also had to check with SMS what they had done to identify over boost. They seem 100% certain that over boost is the source of the problem and have confirmed over boost electronically. Tried your suggestion of disconnecting battery overnight. Doesn't seem to have worked - warning light came on again within 10 mins driving (although the 'shut-down' hadn't kicked in by end of 20 min trial run).

Still waiting on SMS answers to your other queries re checking that correct pipes go to the solenoid valve, and whether they have the electronic workshop manual.

Tks for your time

 

[Wreckless]

Tks extreme-4x4. Have reasonable faith in my local diesel specialist who assures me that they have checked all the mechanical elements of my problem - everything performs as it should. They believe the problem rests within the ECU and it faling to signal the release of excess pressure when over boost occurs.........

...........but then I REALLY am not a mechanic, so what do I know :confused

 

[Wreckless]

Tks dadba. Nissan and A.N.other confirmed that intercooler was defintely split. But no smoke trail. And no turbo noise (although have some new slight hiss/whistle noises since return from SMS Diesels last week). SMS also swapped Air Flow Meter from another same model Patrol but made no difference.

SMS still believe problem originates within ECU. Electronics are not their 'thing', they can only recommend I go back to Nissan. However, since that is where I started and Nissan originally told me the computer showed the problem as being the diesel injector pump (that discounted by SMS), I don't have any confidence in going back to them.

Meanwhile I am saving myself a fortune in fuel driving around in the wife's Fiesta while my (less than) trusty steed sits in worksops or the front drive. Every cloud has a silver lining

 

[zippy656]

Tks dadba. Nissan and A.N.other confirmed that intercooler was defintely split. But no smoke trail. And no turbo noise (although have some new slight hiss/whistle noises since return from SMS Diesels last week). SMS also swapped Air Flow Meter from another same model Patrol but made no difference.

SMS still believe problem originates within ECU. Electronics are not their 'thing', they can only recommend I go back to Nissan. However, since that is where I started and Nissan originally told me the computer showed the problem as being the diesel injector pump (that discounted by SMS), I don't have any confidence in going back to them.

Meanwhile I am saving myself a fortune in fuel driving around in the wife's Fiesta while my (less than) trusty steed sits in worksops or the front drive. Every cloud has a silver lining

just read this, you swapped the air flow meter from another patrol, would it be possible to " borrow" the ecu. the check that out too??

 

[davemud]

Have you done the pipe check if the pipes are worng way round on the contol valve it wont vent to the air box and you get over boost ??

After talking to day with auto mec just try this remove the vacuum feed tube from the control valve (centre pipe on control valve) and put the vacuum pipe directly onto the turbo waste gate actuator that sits on top of the turbo will give you less turbo wind up but should not over boost.....
I Have tested this on my mota today runs but with slightly less power definatly no over boost

Just one last thing is your exhaust OK and is it the standard size and not blowing...most important
If not as with mine patrol running on 3" exhaust system there is less back pressure and you get over boost because the turbo can spin faster.

There is an adjustment for this on the nissan patrol forum, but i have fitted a dawes valve into my vacuum line this is a type of control vale stopping the over boost or you can adjust the variable vains on the turbo itself via the threaded bar and lock nut under the actuator

If you need help tracing the pipes give me a pm we can exchange numbers

 

[Wreckless]

Tks zippy656. This was considered at the time but apparently this is not an option. Either impractical or the borrowed ECU would have had to be re-programmed for my vehicle??

 

[Wreckless]

Hi davemud. Tks again. Confirmed with SMS that a) pipes are fitted correctly to the control valve, and b) that they tested the vehicle, having dropped the exhaust, and were able to exclude the exhaust as possible cause. He was a bit puzzled about the dawes valve comment but accepts that his lack of understanding is most likely a terminology issue rather than a difference of opinion

 

[Wreckless]

Overboost problems

Back in the claws of Nissan :hmh Having asked my local agent to read error message on EMS, the turbo pressure hose split while they test drove (presumably deteriorated due to constant over boost)...... still its 5+C today and Spring is around the corner, so it's not all bad

 

[Jocky]

Hope you get it sorted:thumb2

If you don't already know, you've probably read this on Patrol4X4, some early 3.0ltr Y61's are known as grenades due to the engines blowing. I wonder if they had the same problem your getting?
The dodgy engines are between 2000 & 2003 I think!!!

If and when you get sorted, please post details for others:thumb2

 

[Wreckless]

Tks Jocky. Maybe I had a 'grenade' originally. Who knows. I've this from new. It was recalled within 6-9 months to have a larger sump fitted to increase oil capacity. Then, within another 6 mths it was recalled again - for a new engine this time. 17K mile and a new engine under warranty, so I didn't complain. Whatever the problem was it was not apparent on my brute - it has been going like a train.....until 120K miles when it started this serious overboost carry-on

 

[alan hedges]

Does anyone know the standard boost pressure on the RD28 engine? Y61 Patrol GR 2.8TD?

Ive got a boost gauge in mine and Im not sure if the boosts been fiddled with, it was reading 1.1bar on a cold night

 

[Jocky]

Does anyone know the standard boost pressure on the RD28 engine? Y61 Patrol GR 2.8TD?

Ive got a boost gauge in mine and Im not sure if the boosts been fiddled with, it was reading 1.1bar on a cold night

I've got a boost gauge on mine and the max I see is 15psig, mines is an electrical sender gauge. So you are reading slightly higher.

Mines is taking the reading from the back of the intercooler just before the throttle body

Is you gauge mechanical or electrical and where is it taking the reading?

 

[alan hedges]

Its T'd into a line off the intercooler, electrical sender. Seems to have a one way valve on it as it doesnt read any negative boost or vacuum when off throttle

 

[(RIP) PLANK]

1 bar is 14.7 psi so allowing for your guage reading sligtly high, 1.1 bar isn't far out. Assuming that rewading is acurate. 0.1 of a bar would be 1.47 psi so less than 10% higher and i don't think any guage would be that accurate.

Are you sure its overboosting, what are the symptoms of the problem?