Volvo Owners Club Forum - View Single Post - D5 (D5244T to 2005) - Diesel Knock after fitting a replacement injector

thePM · Mar 7th, 2011, 00:46

Hi, this is my first post here. I have had a good look at existing posts - some such as spee are having related issues but nothing quite the same as the knocking under load since fitting an injector that I am getting. I would appreciate any ideas/recommendations..

I have 2003 D5 XC90 105000 miles full volvo dealer servcing. It recently had the drive shaft spline replaced at a local independent volvo specialist as my dealer said they were not familiar with the loss of AWD issue... anyway whilst the car was with the independent he offered to fix poor idle when cold which I had put down to a tired injector but was going to leave until the car was next due for service.

Injector 5 was identified as having a higher fuel return and was replaced with a '36000288 Injector' - £240 inc VAT + fitting. From the forums the number quoted appears to be for a genuine volvo reconditioned item but I was told this was a new item direct from Bosch. I have noted that the independent has used an old plastic cap (with oil and dust on it) so from a visual inspection it is not possible to verify the actual part no. on the car - the cap is a volvo type 2.

Since fitting the car now starts and runs very smoothly and when revving in neutral sounds perfect. However when accelerating there is a knocking noise from 2000rpm upwards that gets louder with load - it sounds to me like pinking. In the 4 years I have had the car it has never made this noise before.

I took it back to the independent and he agreed he could hear the noise but having not heard the car before said he had no comparison. He suggested the noise may be piston slap or a build up of carbon on the piston. He was sure it wasnt related to the injector. However I have since tried unplugging the injector cable and at similar light acceleration/2000rpm the noise has gone completely (although there is then only limited power due to the engine mgt stepping in).

I am concerned as I am shortly going to be driving the car to the alps at high speed and load and if it is pre-ignition i dont want to damage a piston or valves... The independent has said he is confident it will be fine but I am not convinced.

Going to ask the independent tomorrow for the exact bosch part used and re- confirm new but i'm not sure what my next step is.. my thought is to take it to volvo but I am concerned that they will want to replace all the injectors and I cant really afford that especially if its not completely necessary...

thanks in advance for any help...

Mar 7th, 2011, 00:46	#1
thePM New Member Last Online: Jun 15th, 2012 20:39 Join Date: Mar 2011 Location: Ashtead	Diesel Knock after fitting a replacement injector Hi, this is my first post here. I have had a good look at existing posts - some such as spee are having related issues but nothing quite the same as the knocking under load since fitting an injector that I am getting. I would appreciate any ideas/recommendations.. I have 2003 D5 XC90 105000 miles full volvo dealer servcing. It recently had the drive shaft spline replaced at a local independent volvo specialist as my dealer said they were not familiar with the loss of AWD issue... anyway whilst the car was with the independent he offered to fix poor idle when cold which I had put down to a tired injector but was going to leave until the car was next due for service. Injector 5 was identified as having a higher fuel return and was replaced with a '36000288 Injector' - £240 inc VAT + fitting. From the forums the number quoted appears to be for a genuine volvo reconditioned item but I was told this was a new item direct from Bosch. I have noted that the independent has used an old plastic cap (with oil and dust on it) so from a visual inspection it is not possible to verify the actual part no. on the car - the cap is a volvo type 2. Since fitting the car now starts and runs very smoothly and when revving in neutral sounds perfect. However when accelerating there is a knocking noise from 2000rpm upwards that gets louder with load - it sounds to me like pinking. In the 4 years I have had the car it has never made this noise before. I took it back to the independent and he agreed he could hear the noise but having not heard the car before said he had no comparison. He suggested the noise may be piston slap or a build up of carbon on the piston. He was sure it wasnt related to the injector. However I have since tried unplugging the injector cable and at similar light acceleration/2000rpm the noise has gone completely (although there is then only limited power due to the engine mgt stepping in). I am concerned as I am shortly going to be driving the car to the alps at high speed and load and if it is pre-ignition i dont want to damage a piston or valves... The independent has said he is confident it will be fine but I am not convinced. Going to ask the independent tomorrow for the exact bosch part used and re- confirm new but i'm not sure what my next step is.. my thought is to take it to volvo but I am concerned that they will want to replace all the injectors and I cant really afford that especially if its not completely necessary... thanks in advance for any help...