Citroen C5 x7 156thp, multiple faults. Hpfp, throttle body?

[Jaanne]

Hello, I have this car in my household. VIN: VF7**************[VIN obfuscated, can be read by forum staff]. It has been experiencing various problems recently. When you start your car in the morning to go to work, it may run poorly and sometimes even shut down. Sometimes the fan starts screaming at full blast also and after restarting the engine, everything works properly.

I read the fault codes from the car every time, the first time there was only P0087 (rail pressure too low). I checked the live data, the pressure was at its lowest 49bar (never dropped below that?) and at its highest about 120Bar while driving. Seems right.

Next time there was multiple faults, P1336 (misfires), P1337 (misfires cylinder 1.), P1340 (misfires cylinder4.) I cleared the fault codes and they didn't come back.

The third time there were more errors. P0087 (rail pressure too low), P0171 (mixture control, fuel-air mixture), P0565 (Cruisecontrol?). This time there was also a fault in the automatic transmission. The transmission and handbrake warning lights were on. there was U1208 (No communication with engine ecu) and P1605. Again i clear all because everything works normal.

This morning when I started the car, the engine started fine but the fan was screaming at full blast. I checked the fault codes and there were P061F and P3010, I think these are throttlebody error codes?

Troubleshooting is not helped by the outside temperature which was -22°C. So I drove the engine to warm up. While reading the fault codes the car started blowing cold air, when I increased the revs it started blowing warm air again. The engine temperature remains normal. There may have been a little too little coolant, but I don't think it has that much of an effect. So i think i have broken waterpump.. Also i chek heating/aircondition fault codes. There was nothing but i noticed, right-hand outflow temperature sensor is broken. 6513,5°C. Left-hand works and reacts normal.

I removed the engine control unit and fuse box, hoping to see a fault in the connectors or wires, but everything looked fine...

I read various forums and apparently there has been a problem with HPFP, could it be causing these issues? New pump cost allmost 800€, very expensive to buy, try and hope. What do I do next with this car, drive to the sea and forget?

[mickthemaverick]

As many random faults as this often turns out to be a poor battery condition. I'd give the battery a good overnight charge and then carry out the BSI reset according to the procedure in the link below. Also check that you have no leaks around the injectors as they can cause fluctuations in fuel pressure and resultant misfires. Once the battery is charged then clear all the fault codes and see what returns.

https://frenchcarforum.co.uk/forum/view ... 79#p601679

[Jaanne]

I was thinking that cold air blowing issue. I dont believe that main waterpump is problem, because engine temperature is normal and not overheating. I notice there is auxilary waterpump too, in citroen that might called turbo waterpump? Would that be the problem? Today i'm going to add coolant and possibly bleed the cooling system if there were any air locks left in there for some reason. At the same time i could test if the other pump work properly.

[Paul-R]

Bleeding is a good point to have a look at.

[Jaanne]

Today I checked the car again. Adding coolant and bleeding the cooling system helped get warm air into the car. I also checked that this "turbo water pump" is working properly. In the summer, when I went on vacation, I checked and added coolant to the maximum level. Now I was able to add almost 1L of new coolant. There was no visible leak anywhere. Somethink is drinking it...

I checked around the injectors. Really hard to see, I could only see the two injectors on the transmission side. The throttle body blocked the view of the first two. Everything looked really dry and clean. I also tried spraying Brake cleaner there, hoping there would be a leak and the engine would rev up. But nothing happened. I also checked the fault codes, there were none of them.

During the last 10 driving cycles, the computer has only recorded 2 misfires in cylinder number 2. and 1 misfire, in cylinder number 3. None in the other cylinders. I also took a short video clip showing some live data. Sorry for the poor quality at the beginning of the video.
https://1drv.ms/v/c/ba36786a63c6e16a/IQ ... A?e=ISaf4d

I measured the fuel pressure with a mechanical gauge. It was about 5Bar.

I had already done a battery test before. I forgot to mention that in the first message. According to it, the battery would already be bad. The battery is 2-3 years old, can it already be so bad that it causes these problems? The battery is a Bosch S5 008. 12V 77Ah 780A.

Edit: Add one photo. The car is working completely normally again for now. Does any of the data show anything unusual?

[mickthemaverick]

When I searched for your battery I found the link below which suggests the battery has a 5 year warranty. I'd check your receipt for it, if it is only 2-3 years old and see if they will replace it under warranty. Yes any battery can die at any time due to excessive charge/discharge cycles or high level rapid discharge, often caused by continuous cranking of a non starting engine, or even inadvertant short circuiting etc. Replace it and see how it goes:

https://www.powerland.co.uk/products/s5 ... -096-s5008

[Jaanne]

Yesterday the car was driven for about 400 km. Everything works fine. The car was parked outside for a couple of hours, then we went for a drive. Fault lights on the dashboard and really bad running. No power... This morning my partner took the car to the store, again poor idle and everything was bad. Nothing had been fixed during the night. When I got home from work in the evening I started reading the fault codes. P0172, P061F, P0565, P3010. So this time issue is throttlebody. Could that be the reason for everything?

I found this old topic on this forum where these error codes are explained. https://frenchcarforum.co.uk/forum/view ... hp?t=75642

Then, when I get the car warm and have time to investigate, I think I'll try to examine that throttle body with a diagnostic device. Luckily, it's not an expensive part.

[Jaanne]

Hi again, The car has been working perfectly for almost three weeks. Yesterday, when the outside temperature was -20, the car was put in the heater for two hours. My lady tried to drive the car to work. The idle was bad and the car was jerking, after 200m the car had frozen and could not move forward, then it suddenly moved, the next 100m it froze again. Then it moved again and worked fine until work. The fan had been screaming at full blast the whole journey. The journey home from work went smoothly, everything worked normally.

Today I read the fault codes, this time they were, P0087, P1336, P1340, P1338. The car worked perfectly again. No misfires were detected or any other problems. Rail pressures were normal etc. I clear all faults..

Using the Bosch KTS560 test device, I was able to examine the throttle valve more closely and, at least for now, it was working normally. I suspected this throttle valve fault in my previous post.

I checked the battery warranty, unfortunately here in Finland we don't have such long warranty periods for batteries. I don't think the battery is that bad it could cause such problems on its own, at least other car brands haven't had this. Of course, with a new battery this option would also be ruled out, it's a approx. €150 experiment.

I'm starting to get frustrated with this problem.

[PaulC5]

A search suggests it could be the high pressure fuel pump is failing. An example topic https://www.peugeotrczforum.com/threads ... xed.15280/

[Jaanne]

A month ago I ordered and replaced a new throttle body and gasket. I ordered a Hitachi (Astemo) one from Autodoc. The original one seemed to be made by Continental. I noticed that there was a little oil in the throttle body connector, the wiring harness itself was completely dry, so the oil must have come from inside the throttle body. I think moisture/oil has gotten in from the shaft root and it has caused these problems in very cold weather. Now, after a month of driving, all fault codes related to the throttlebody, transmission, handbrake or cruisecontrol are gone!

Half Victory!

[Jaanne]

The car still has problems when starting. It runs poorly, stutters and has no power. P0087 and a few missfire fault codes still come up. I have tried reading the fault codes many times but the car always works normally. Low pressure is 5bar and High pressure is 50bar. There is a very high probability that the fault is in the HPFP pump but it bothers me that I can't get proof of it. A new high pressure pump is so expensive that I will lose my balls if I tell her to buy a new one and the fault is not there..

[Jaanne]

Happy spring to all forum members! I finally made a decision and ordered a new hpfp for the car. I ordered it from Trodo for 603€. The brand was Hoffer. Google's ai told me that it is a company owned by the Meat & Doria and they are practically the same parts, in different packaging. This new Hoffer pump had the M&D logo, so apparently this information was correct. The replacement was easy. In hindsight, it probably would have been worth replacing the pipe between the pump and the nozzle rail as well. Apparently it is recommended to replace both at the same time. After replacing the pump, the car has been working perfectly for a week. No more cold start problems or error codes! The fault was indeed HPFP!


I also noticed that with the hood open the car sounds a little stuttery at idle, not much but a little. I think it has been doing this for a while now. I think I'll change the spark plugs in the car too!

So that life wouldn't be too easy and comfortable, I bought myself a completely identical car! The only differences are color and that my car doesn't have half-leather seats, but I have a glass roof!
The seller of the car lives +300km away and his car broke down in my town. The local repair shop examinded the car and stated that the 2nd cylinder injector is broken, it is leaking through. The owner managed to get another ride home and wanted to get rid of this car quickly. He put it up for sale for €500, I bought it right away! New Bosch injectors seemed to cost 65€/each. I think I will replace all 4 of them and see what happens!