2.0 D4D Losing power when engine temp rises

[AlmaPiim]

So my mom bought a 2005 Avensis, 2.0 D4D. At first it drove fine and was really economical, but then the problem started. In the beginning while in 5th gear, it would sometimes lose power and a bunch of dark smoke would come out. The problem got solved (at the time) by going into 4th and accelerating. Over time it got more frequent and now when it goes w/o power, there's no getting it back, unless the engine cools all the way down. Its thrown a
P1251-Step motor for turbocharger control circuit (intermittent)
and
P0400-EGR flow fault codes. I tried cleaning the EGR valve but that didn't do anything so I'm not sure if that isn't the problem, or I didn't clean it well enough. I'm an intern in a workshop so I had our diagnostic diagnose it. He also went for a test drive and when accelerating, a bunch of brown smoke came out. He checked live data and found that injector #4 is on it's way out (but that in my opinion couldn't cause the loss of power when engine is warm) and the accelerator position sensor wasn't giving the right signal so I installed a new one. He told me to test drive to see if the problem was gone, but it wasn't. Also before, the loss of power would come, when the temp gauge would be 2 lines from operating temperature, but today it's started to lose power right as the temp gauge starts to rise. He's going on a vacation now so I'm trying to search for the problem myself, but he suggested something with turbo.

[Cyker]

IIRC that has a variable vane turbo; It sounds like the mechanism that moves the vanes is overheating and jamming or something.

I remember reading about people on here having similar problems in the past but can't remember what the fixes were...

 

[DerekHa]

Hi Ayman,

I had problems with ERG valves on a number of my previous diesel engined vehicles in the past. From your symptoms, though not exactly the same, my immediate inclination would be it's the ERG system that causing your problems. Should also add that I've never owned or worked on the Avensis 2.0 D4D.

I appreciate you've cleaned the valve itself, they're a nightmare to clean thoroughly and sometimes need replacing. Have you checked the inlet manifold and cleaned that out? I'm sure I've read that there are internal passages inside the manifold that can get totally blocked to the point it really affects the running of the engine.

There's a video I've posted a link to on youtube that shows the removal of the EGR valve, throttle body, manifold etc and cleaning. Worth a watch at least as it shows a badly choked up manifold ect.

The fact there's a faulty injector could contribute greatly to carbon build up inside the manifold/EGR through the unburnt fuel.

Others here may have different ideas and actual experience with that engine.

Hope you get to the bottom of the problem.

 

[AlmaPiim]

On 12/15/2022 at 8:25 PM, Cyker said:

IIRC that has a variable vane turbo; It sounds like the mechanism that moves the vanes is overheating and jamming or something.

I remember reading about people on here having similar problems in the past but can't remember what the fixes were...

 

Thank you for the idea, I don't feel comfortable getting to the turbo yet so I will pass this info to my diagnostic when I bring the car to him.

[AlmaPiim]

On 12/15/2022 at 8:48 PM, DerekHa said:

Hi Ayman,

I had problems with ERG valves on a number of my previous diesel engined vehicles in the past. From your symptoms, though not exactly the same, my immediate inclination would be it's the ERG system that causing your problems. Should also add that I've never owned or worked on the Avensis 2.0 D4D.

I appreciate you've cleaned the valve itself, they're a nightmare to clean thoroughly and sometimes need replacing. Have you checked the inlet manifold and cleaned that out? I'm sure I've read that there are internal passages inside the manifold that can get totally blocked to the point it really affects the running of the engine.

There's a video I've posted a link to on youtube that shows the removal of the EGR valve, throttle body, manifold etc and cleaning. Worth a watch at least as it shows a badly choked up manifold ect.

The fact there's a faulty injector could contribute greatly to carbon build up inside the manifold/EGR through the unburnt fuel.

Others here may have different ideas and actual experience with that engine.

Hope you get to the bottom of the problem.

 

When I was cleaning the EGR, I could see the passages going from the valve itself so I tried to clean those also, but they curved right after leaving the valve so I couldn't clean much. The video was helpful in giving a general idea on what to do, unfortunately it was for a different engine layout. In the video the EGR is in a easily accessible place, on my car, its on the gearbox side of the engine and in the back.

[DerekHa]

2 hours ago, AlmaPiim said:

When I was cleaning the EGR, I could see the passages going from the valve itself so I tried to clean those also, but they curved right after leaving the valve so I couldn't clean much. The video was helpful in giving a general idea on what to do, unfortunately it was for a different engine layout. In the video the EGR is in a easily accessible place, on my car, its on the gearbox side of the engine and in the back.

Sorry that that link didn't cover your particular engine Ayman. At least it's given you some indication of what needs cleaning and I'm sure youtube will have a howto on your mum's engine. Which engine is it by the way?

Everything on that engine was easily accesible and right at the front of the vehicle I know. Worse car I had problems working on an EGR valve was a 2006 Vauxhall Astra 1.3cdti Estate. It took me 4 days to remove clean and refit the EGR valve! Never completely cured the issue, relatively minor in comparision to what you describe, but the valve was placed low down on the rear face of the engine close to the bulkhead all complicated because Vauxhall choose to water cool the valve it self. My ham strings were painful for ages after from having to stretch so far to reach the thing.

Let us know how you get on please.

[AlmaPiim]

3 hours ago, DerekHa said:

Sorry that that link didn't cover your particular engine Ayman. At least it's given you some indication of what needs cleaning and I'm sure youtube will have a howto on your mum's engine. Which engine is it by the way?

Everything on that engine was easily accesible and right at the front of the vehicle I know. Worse car I had problems working on an EGR valve was a 2006 Vauxhall Astra 1.3cdti Estate. It took me 4 days to remove clean and refit the EGR valve! Never completely cured the issue, relatively minor in comparision to what you describe, but the valve was placed low down on the rear face of the engine close to the bulkhead all complicated because Vauxhall choose to water cool the valve it self. My ham strings were painful for ages after from having to stretch so far to reach the thing.

Let us know how you get on please.

The engine in my mom's car is the 1CD-FTV, as the engine in the video is also 2.0 D4D, I believe it's the 1AD-FTV. On the 1AD, the EGR is in front of the engine, easily accessible, but on the 1CD it's in the back, it's more difficult to get access to.
The EGR on the 1CD is also watercooled I think (since there's 2 hoses attached to it.

[DerekHa]

Take it this is the manfold the EGR is bolted to?

https://www.ebay.co.uk/itm/152523442620

If you do decide to remove the manifold and clean it out you could try using oven cleaner inside there, it will melt a loaded of the built up carbon and thick black deposites, then wash out with hot water. You will likely need to repeat several times. Check to see if there are any small galleries/drillings that are blocked internally.

 

 

[AlmaPiim]

1 hour ago, DerekHa said:

Take it this is the manfold the EGR is bolted to?

https://www.ebay.co.uk/itm/152523442620

If you do decide to remove the manifold and clean it out you could try using oven cleaner inside there, it will melt a loaded of the built up carbon and thick black deposites, then wash out with hot water. You will likely need to repeat several times. Check to see if there are any small galleries/drillings that are blocked internally.

 

 

Thanks for the Idea. I'm not sure about that, but at least I'll know what to use when I get to it

[AlmaPiim]

Update: the car went to another diagnostic that specializes with Toyotas. He said that the turbo needs to be replaced as it is not functioning (as in the vanes don't move) and that injector #4 is basically done. I then got the idea to add diesel injector cleaner to the fuel so I did that. Also had the idea to drive a lot more agressively (as in changing gear at 4k rpm and steadily driving at around 3k-3,5k rpm. I drove like that to work and back every day from monday til today (friday) and to my surprise, the car drives better than before. Before, the power would cut out as soon as the temp gauge started rising, but now I can drive until the gauge has risen a couple of lines. Yesterday and today was the first time in a couple of months, that the car has reached 100km/h. I ordered a new injector to replace injector #4 and I will try to replace it tomorrow. My guess is that agressive driving has atleast a bit burned out the soot from the turbo(why the vanes might be stuck) but since injector #4 is faulty, it still produces soot so the turbo doesn't have time to be burned clean. Will update.

[DerekHa]

Hi again Ayman,

Sounds like you may on your way to saving a fortune if the cars performance has  improved by using a fuel additive and driving it hard, turbo diesels are designed for hard fast driving not intended to be driven around town at lower speeds.

Hopefully replacing that bad injector will make more of a difference and that turbo of yours will free up.

[AlmaPiim]

I sure hope it will :D. I will try replacing the injector tomorrow. But since I don't have a puller, I'm gonna have to see if I can even get the old injector out

[Cyker]

Yeah it does sound like the turbo vanes just need to be un-sooted; If you have a cleaner burning diesel available like Shell V-Power diesel, it might be worth running a few tanks of that through it, otherwise your preferred fuel system cleaning additive.

But getting the engine good and hot definitely helps - My old Mk1 D4D would get really sluggish if I drove it gently all the time. I used to visit my brother more often in that car as it was a good excuse to hoon the thing along the fast bits of the A5 and get the engine good and hot!  

Bizarrely I'm starting to feel like my Mk4 Yaris has a similar need, as it starts acting a bit weird if I haven't taken it on a thrash for a while.

 

[DerekHa]

Good luck with getting that injector out, have never done one myself but did have one replaced by my trusted mechanic who warned me before that getting one out could be problematic! They often won't play nice I understand!

[AlmaPiim]

On 1/13/2023 at 9:57 PM, Cyker said:

Yeah it does sound like the turbo vanes just need to be un-sooted; If you have a cleaner burning diesel available like Shell V-Power diesel, it might be worth running a few tanks of that through it, otherwise your preferred fuel system cleaning additive.

But getting the engine good and hot definitely helps - My old Mk1 D4D would get really sluggish if I drove it gently all the time. I used to visit my brother more often in that car as it was a good excuse to hoon the thing along the fast bits of the A5 and get the engine good and hot!  

Bizarrely I'm starting to feel like my Mk4 Yaris has a similar need, as it starts acting a bit weird if I haven't taken it on a thrash for a while.

 

Yup, TD-s need to be driven rough or something will clog up 😄

[AlmaPiim]

On 1/13/2023 at 10:00 PM, DerekHa said:

Good luck with getting that injector out, have never done one myself but did have one replaced by my trusted mechanic who warned me before that getting one out could be problematic! They often won't play nice I understand!

I tried replacing the injector today and after wiggling it a bit, it came out. I was also told ''good luck getting that injector out without a puller'', especially because the car has 432k km on the clock. I wasn't the only one surprised by that. Unfortunately the injector that got sent to me, was not the right one, and I found it out only after disassembling everything and getting the old injector out 😄 . Didn't occur to me to check it before, because when I sent out a spare part request I filled out everything about the engine (engine code, size, how many kw etc). I ordered a new injector and this time I checked more carefully so at least when I get the time to replace it, I sort of know what to do.

[AlmaPiim]

Also when driving to the shop to replace the injector, I felt power coming back sooner (at around 3k rpm) than yesterday (around 4k rpm). Will drive a couple of days to see if it gets any better.

[DerekHa]

Good to hear to your still seeing an improvement despite not yet having the correct injector. I dare say that you still have that fuel treatment in the tank and it's still at work while your driving around waiting for your new injector. 👍

[AlmaPiim]

Final update: couldn't get the injector washer out so the car went to a workshop that specializes with diesel engines. After the washer got replaced and a new injector put in, the mechanic called me about the no power problem. Explained to him the whole story and he said it felt like the car was chocking on its own exhaust, asked maybe I would want to have it diagnosed. Said f-it and gave him the green light. Today he called me and said the car drives perfectly. He checked the EGR and it was stuck half open, but it didn't give any fault codes. He then put a plate on the EGR valve and it still didn't give any fault codes BUT, the car drives perfectly. His guess is that the EGR was programmed off, but the plate to block off the EGR had maybe burned through. Atleast the problem is now fixed and the car can be driven normally :D. Thank you everyone for your suggestions.