|
||
|
10th July 2020, 17:53 | #31 | |
Regular poster
MG ZR Join Date: Jun 2020
Location: Newcastle Upon Tyne
Posts: 93
Thanks: 53
Thanked 30 Times in 19 Posts
|
Quote:
I’m replacing the turbo, just received my reconditioned unit. I’ll be updating soon with the results. |
|
10th July 2020, 18:32 | #32 |
Gets stuck in
Rover 75 Saloon Join Date: Jan 2010
Location: Preston
Posts: 624
Thanks: 50
Thanked 44 Times in 32 Posts
|
I read your post the other night but you appeared to have already checked the waste gate so I didn't provide you with a response I gave in 2011. However as you do not appear to have resolved your problem I thought I would provide it, it may be of some value:
When I had a ZT 1.8T it would pitch violently when it hit 4000rpm. I traced it to the pivot seizing where the waste gate actuator arm attaches to the waste gate. This stopped the actuator from opening the waste gate and the resulting over boost tripped the ignition cut out to protect the engine. I removed the spring clip and prised off the arm. I cleaned the pin and the hole and reassembled with a special high melting point anti seize spray. I also cycled the waste gate several times every few weeks. To do this I traced the small bore pipe from the waste gate actuator up to the ignition cut out (think it was on the battery box). I pulled the pipe off the cut out and carefully pressurised it with an electric tyre pump. You can just see the arm/waste gate if you look down from above. The arm will move across then you should stop the pump when the arm reaches the end of its travel. If you over pressurise you may rupture the diaphragm in the actuator. It only took about 15-20 psi to reach full travel. |
15th July 2020, 15:27 | #33 |
Regular poster
MG ZR Join Date: Jun 2020
Location: Newcastle Upon Tyne
Posts: 93
Thanks: 53
Thanked 30 Times in 19 Posts
|
Update.
I checked the wastegate actuator operation and to me it looked to be operating. I took the car to my local garage for a second opinion, they confirmed the wastegate actuator appeared to be working. They suspected a possible internal fault with the turbo and recommended I had it sent off to to be tested. Given how much of an inconvenience this would be I decided to get a reconditioned complete turbo. The cost of a reconditioned turbo actually was more cost effective than having mine removed and sent off for testing. So to eliminate any possible issues that may be being caused with the turbo or actuator, the turbo assembly has been replaced. Now the really annoying part, the problem still persists. Only now it seems to happen slightly later in the rev range. I’m at a point where I’m giving up. It’s been on Marinabrians T4 where overboost was conformed. Suspect was dodgy MAP sensor wiring, this is now replaced. No change. Plugs renewed and gapped to 0.6mm, no change. Boost solenoid replaced with a new one, no change. Boost solenoid bypassed, no change. Now complete turbo replaced, no change. There’s nothing left to change. I’ve had three separate opinions on the issue and have been told it’s not the coils so no need to replace them. I’m beginning to wonder if it’s worth doing them anyway just to add something else to the list of eliminations. Along with a new MAP sensor perhaps, but this is just clutching at straws now and I’m throwing money at a cheap old car for no gain. I love these cars I really do, but I’m getting pretty NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD- off with it now. Last edited by Mean & Green; 15th July 2020 at 15:33.. |
15th July 2020, 17:56 | #34 |
Gets stuck in
Rover 75 Saloon Join Date: Jan 2010
Location: Preston
Posts: 624
Thanks: 50
Thanked 44 Times in 32 Posts
|
Have you pressurised the waste gate actuator and confirmed that the arm between the actuator and the waste gate moves through the normal amount of travel. It is at least 10 years since I did this test so I cannot remember how much it moves but it is visible looking down from above. I used a 12V electric pump to pressurise the actuator and I monitored the pressure I was applying with a gauge. I connected the pipes and the gauge with the pump off then the switched the pump on while watching the arm. It moved across as the pressure increased and as soon as the arm reached the end of the travel I stopped the pump so I did not over pressurise and damage the actuator diaphragm. The arm reached the end of its travel somewhere between 15 and 20psi.
|
15th July 2020, 18:03 | #35 |
Posted a thing or two
Rover 75 Cont SE 1.8T Join Date: Aug 2010
Location: Cheshire
Posts: 1,082
Thanks: 215
Thanked 232 Times in 178 Posts
|
Fair play for your determination to solve the issue. Hopefully you'll come to a solution.
__________________
Rover 75 1.8T Contemporary SE Auto Starlight Silver MBB |
15th July 2020, 18:53 | #36 | |
Regular poster
MG ZR Join Date: Jun 2020
Location: Newcastle Upon Tyne
Posts: 93
Thanks: 53
Thanked 30 Times in 19 Posts
|
Quote:
I’ve just replaced the whole unit including the wastegate actuator. It can’t be that now at this stage. The only thing I haven’t replaced is the coil packs which I think I’m going to do anyway to 100% eliminate them. |
|
15th July 2020, 18:56 | #37 | |
Regular poster
MG ZR Join Date: Jun 2020
Location: Newcastle Upon Tyne
Posts: 93
Thanks: 53
Thanked 30 Times in 19 Posts
|
Quote:
The car drives brilliantly if I never ever put my foot down, not much use when it comes to overtaking manoeuvres though. |
|
17th July 2020, 10:07 | #38 |
Regular poster
MG ZR Join Date: Jun 2020
Location: Newcastle Upon Tyne
Posts: 93
Thanks: 53
Thanked 30 Times in 19 Posts
|
It’s been suggested to me that the retrofitted alloy inlet manifold can cause vacuum leaks due to the mating surfaces not matching up correctly.
Someone else has experienced the same issues as me and replaced everything with no success only to find that the upper section of the manifold wasn’t sealing correctly. So I have something else to investigate further now. Coil packs are on order as well, probably won’t make any difference - but at this stage I may as well just swap them anyway I’ve replaced everything else what’s another £38 for a pair of new coils and piece of mind Not giving up hope yet. |
17th July 2020, 10:14 | #39 |
This is my second home
Roverless + 1.7D Sportage Join Date: Aug 2014
Location: East Norfolk
Posts: 7,050
Thanks: 729
Thanked 2,021 Times in 1,449 Posts
|
There was a service bulletin about coil leads breaking down where they fit onto the plugs. My V6 suffered with this lead problem and as only the front bank has leads (on the V6) I hadn't considered it. A change of leads and the problem was solved. On examination, the connections to the plug tops were badly decomposed and the spark must have been jumping the gap and burning. The carbon in the leads also becomes brittle over time and can give intermittent spark problems under load.
__________________
Oil in my veins! |
17th July 2020, 12:28 | #40 | |
Banned
Health Join Date: Sep 2019
Location: Usa
Posts: 44
Thanks: 7
Thanked 26 Times in 11 Posts
|
Quote:
|
|
|
|