Brake booster(?) and intercooler problem

Alexandru.Edward · 17th June 2018, 20:29

Hello everyone.
I have 2 problems with my Rover 75 Saloon 2.0 CDTI 204D2 engine, 2003 year.

First problem:
I'm driving in a gear with 2000 RPM and when it comes to a stop, I get the car out of gear and when the RPM are still droping, if I press the brake pedal the car wil not stay at idle RPM, it will stay at 400-500 RPM until a complete stop, when the RPM goes back to normal. If I depress the pedal when the car is at 500 RPM but still in motion, the RPM goes back to normal as well, even if I'm not stopped yet. I think it's a vacuum leak, but I don't know where to look, which hose can make this happen.

Second problem:
My car makes a strange air noise when it's in load. It comes from the right side of the engine (when you look at the car from the front). At idle the noise it's not present, even if I rev the car. It's more like an air escaping sound, not the "whoooosh" sound from the turbo. The turbo it's verified and doesn't have a problem. It can be the intercooler hose O rings? I don't think the intercooler itself may leak, because the sound it's not a sharp one, it's more like an air fan noise, but with less air and only when it's on load.

Thanks in advance for help!

RoverP480 · 17th June 2018, 22:02

The two may be connected . Depending where it is ,if there is an air leak it can upset the idle as there will can be a mismatch between air flow meter and the actual air getting to the engine. Also is anything stopping your throttle pedal returning fully as if not the anti-stall wont work.

Mike Noc · 18th June 2018, 10:36

Re your first 'problem' this is well known and has been discussed many times on the forum. Nobody has established whether it actually is a problem, or the normal operation of the engine management system.

It is completely controlled by the ECM though - you can prove this by taking your foot off the pedal just as the revs drop to idle, and then re-applying pedal pressure. The revs won't drop any further once stabilised.

As far as I know only the manual cars do it, and I have a TD4 manual Freelander which has never done it.

The vacuum is generated by a pump on the diesels, as the inlet air isn't throttled there is no vacuum to be had in the manifold. The EGR valve is operated by vacuum, but that won't have any bearing on this even if the vacuum drops off.

As for the airflow meter, it does a different job on a diesel compared to petrol cars, so again it won't have a bearing on this as at idle there is so much more air available than needed that a leak in the intercooler/manifold won't cause a problem, and of course the turbo isn't doing much at idle anyhow.

The ECM shuts off fuel completely on the overrun at higher revs, and it looks likely that this is an extension of the fuel saving stratagy, unless anyone has discovered anything new.

As for your second problem; yes change the O rings and inspect the elbow for any splits or holes.

Alexandru.Edward · 19th June 2018, 12:25

Thanks for help. I will change the O rings and inspect the intercooler to see if thw leak it's still there after that.

On the braking problem, I googled it and found something like this:
At the clutch pedal it's a sensor the EMS needs to know when you have the clutch pressed for overrun cut off of fuelling.

It's the sensor broken? Because I don't need to press the clutch to start the car as a safety feature if you forgot that you had it in gear and try to start it.
I think the car does that because EMS thinks that it needs to cut fuel and the anti stall prevents it from dying.

Mike Noc · 19th June 2018, 19:15

You don't need to depress the clutch to start the engine on these cars.

If you have cruise control then it won't work if the clutch sensor isn't sensing the pedal.

Alexandru.Edward · 19th June 2018, 22:34

I don't have CC and I don't want to fit one anyway.
If I unplug the sensor this will disturb something in the car? If not, I'll do that and hopefully get rid of that because it's so annoying.

Mike Noc · 20th June 2018, 08:40

Can't see it disturbing anything else so give it a go and let us know how you get on.

Alexandru.Edward · 20th June 2018, 21:26

IT WORKED!!!
For everyone with this issue, just take out the sensor under the clutch pedal and the RPM will be forever stable, no more drops.
What I can see is that the car it's more responsive under acceleration or probably it's just in my mind.
Here you can see the sensor under the pedal: LINK

Here are some photos of the sensor:
---1---
---2---
---3---

It was a really pain to get it out, but luckily I was able to do that.
Now the car RPM are stable.

When I took it out, I saw a connector hanging here near OBD2 port, do you know what is it?
---1---
---2---

Arctic · 20th June 2018, 22:23

Quote:

Originally Posted by Alexandru.Edward

IT WORKED!!!
For everyone with this issue, just take out the sensor under the clutch pedal and the RPM will be forever stable, no more drops.
What I can see is that the car it's more responsive under acceleration or probably it's just in my mind.
Here you can see the sensor under the pedal: LINK

Here are some photos of the sensor:
---1---
---2---
---3---

It was a really pain to get it out, but luckily I was able to do that.
Now the car RPM are stable.

Quote:

When I took it out, I saw a connector hanging here near OBD2 port, do you know what is it?
---1---
---2---

Hi Edward.
The connector is for the sun shade lights that some of the car have, so if you wanted sun shades with light in them when you pull them down these are the connectors, you will find one on the passenger side too.

Alexandru.Edward · 20th June 2018, 23:24

Oh, didn't think of that, thank you so much!

Great community, I solved all my problems with your help by my own. Thank you guys!

17th June 2018, 20:29	#1
Alexandru.Edward Regular poster Rover 75 Saloon Join Date: Apr 2018 Location: Bucharest Posts: 53 Thanks: 56 Thanked 1 Time in 1 Post	Brake booster(?) and intercooler problem Hello everyone. I have 2 problems with my Rover 75 Saloon 2.0 CDTI 204D2 engine, 2003 year. First problem: I'm driving in a gear with 2000 RPM and when it comes to a stop, I get the car out of gear and when the RPM are still droping, if I press the brake pedal the car wil not stay at idle RPM, it will stay at 400-500 RPM until a complete stop, when the RPM goes back to normal. If I depress the pedal when the car is at 500 RPM but still in motion, the RPM goes back to normal as well, even if I'm not stopped yet. I think it's a vacuum leak, but I don't know where to look, which hose can make this happen. Second problem: My car makes a strange air noise when it's in load. It comes from the right side of the engine (when you look at the car from the front). At idle the noise it's not present, even if I rev the car. It's more like an air escaping sound, not the "whoooosh" sound from the turbo. The turbo it's verified and doesn't have a problem. It can be the intercooler hose O rings? I don't think the intercooler itself may leak, because the sound it's not a sharp one, it's more like an air fan noise, but with less air and only when it's on load. Thanks in advance for help!

20th June 2018, 21:26	#8
Alexandru.Edward Regular poster Rover 75 Saloon Join Date: Apr 2018 Location: Bucharest Posts: 53 Thanks: 56 Thanked 1 Time in 1 Post	IT WORKED!!! For everyone with this issue, just take out the sensor under the clutch pedal and the RPM will be forever stable, no more drops. What I can see is that the car it's more responsive under acceleration or probably it's just in my mind. Here you can see the sensor under the pedal: LINK Here are some photos of the sensor: ---1--- ---2--- ---3--- It was a really pain to get it out, but luckily I was able to do that. Now the car RPM are stable. When I took it out, I saw a connector hanging here near OBD2 port, do you know what is it? ---1--- ---2--- Last edited by Alexandru.Edward; 20th June 2018 at 21:30..

17th June 2018, 22:02	#2
RoverP480 Gets stuck in None at the moment Join Date: Jan 2018 Location: Hereford Posts: 501 Thanks: 1 Thanked 165 Times in 146 Posts	The two may be connected . Depending where it is ,if there is an air leak it can upset the idle as there will can be a mismatch between air flow meter and the actual air getting to the engine. Also is anything stopping your throttle pedal returning fully as if not the anti-stall wont work.

18th June 2018, 10:36	#3
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,547 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	Re your first 'problem' this is well known and has been discussed many times on the forum. Nobody has established whether it actually is a problem, or the normal operation of the engine management system. It is completely controlled by the ECM though - you can prove this by taking your foot off the pedal just as the revs drop to idle, and then re-applying pedal pressure. The revs won't drop any further once stabilised. As far as I know only the manual cars do it, and I have a TD4 manual Freelander which has never done it. The vacuum is generated by a pump on the diesels, as the inlet air isn't throttled there is no vacuum to be had in the manifold. The EGR valve is operated by vacuum, but that won't have any bearing on this even if the vacuum drops off. As for the airflow meter, it does a different job on a diesel compared to petrol cars, so again it won't have a bearing on this as at idle there is so much more air available than needed that a leak in the intercooler/manifold won't cause a problem, and of course the turbo isn't doing much at idle anyhow. The ECM shuts off fuel completely on the overrun at higher revs, and it looks likely that this is an extension of the fuel saving stratagy, unless anyone has discovered anything new. As for your second problem; yes change the O rings and inspect the elbow for any splits or holes.

19th June 2018, 12:25	#4
Alexandru.Edward Regular poster Rover 75 Saloon Join Date: Apr 2018 Location: Bucharest Posts: 53 Thanks: 56 Thanked 1 Time in 1 Post	Thanks for help. I will change the O rings and inspect the intercooler to see if thw leak it's still there after that. On the braking problem, I googled it and found something like this: At the clutch pedal it's a sensor the EMS needs to know when you have the clutch pressed for overrun cut off of fuelling. It's the sensor broken? Because I don't need to press the clutch to start the car as a safety feature if you forgot that you had it in gear and try to start it. I think the car does that because EMS thinks that it needs to cut fuel and the anti stall prevents it from dying.

19th June 2018, 19:15	#5
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,547 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	You don't need to depress the clutch to start the engine on these cars. If you have cruise control then it won't work if the clutch sensor isn't sensing the pedal.

19th June 2018, 22:34	#6
Alexandru.Edward Regular poster Rover 75 Saloon Join Date: Apr 2018 Location: Bucharest Posts: 53 Thanks: 56 Thanked 1 Time in 1 Post	I don't have CC and I don't want to fit one anyway. If I unplug the sensor this will disturb something in the car? If not, I'll do that and hopefully get rid of that because it's so annoying.

20th June 2018, 08:40	#7
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,547 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	Can't see it disturbing anything else so give it a go and let us know how you get on.

20th June 2018, 23:24	#10
Alexandru.Edward Regular poster Rover 75 Saloon Join Date: Apr 2018 Location: Bucharest Posts: 53 Thanks: 56 Thanked 1 Time in 1 Post	Oh, didn't think of that, thank you so much! Great community, I solved all my problems with your help by my own. Thank you guys!