Volvo Owners Club Forum - View Single Post - D5 (D5244T to 2005) - performance issues when car is hot and under load

nstojanoski · Aug 14th, 2017, 20:10

The VNT is changed and now is working in sync with the turbo, but we can't get performance from the car when it's working on normal temp. The last few weeks ware TOO hot here and the performance of the car was like the car has only 60hp not 160hp.

This days the temp is lower and I've made a few videos wit the car is cold (starting it after a night getting cold) and when the car hot after driving for 1 hour.

On this "when cold" video i could get even better performance but the road was not for fast driving, (i had to stop on 4000rpm in 3rd gear)but as you can see i can get to 5000rpm(2nd gear) which is not possible when the car is hot.

[YOUTUBE]https://youtu.be/hKfyVCJaM-I[/YOUTUBE]

This next video is when the car is driven for about 1 hour and the temperature outside is 22C (last few weeks was around 37-38 and the performance ware even worst). Here is when hot and as you can see the RPM's are loading slower and i had open road here and the pedal was pressed full.

[YOUTUBE]https://youtu.be/LipXpLf1KUs[/YOUTUBE]

I think it's something with rubber which is making performance issues when hot, but my mechanic think it's lack of fuel, because he checked for leaks and we don't have black smoke when pressing the pedal, also we have characteristics of not enough fuel on older disel cars.,

One of the first things we changed was the fuel pump which is in the fuel tank under the back seat, but the pump we got was from another car NOT NEW, the old one was just leaking and with this one we had some improvement but we think this is low pressure and we can't find not even in VIDA which the values should be.

Please take a look at the video and tell me if this is OK:

[YOUTUBE]https://youtu.be/IQCJNN27vSw[/YOUTUBE]

At this moment we don't have a car with the same engine to compare but on citroen i think the car is not working if the fuel pump is not making 1.8bars and in our case we don't have even 0.1-0.2 bars, if you put a finger the fuel will stop.

Any ideas before we spend out money on new fuel pump?

Forgot to write we changed the fuel filter when we changed this pump and once again few weeks ago when we tried to clean the fuel system with blowing high pressure air from the engine to the filter and the other way around.

Aug 14th, 2017, 20:10	#4
nstojanoski New Member Last Online: Jul 29th, 2019 20:40 Join Date: Jul 2017 Location: Skopje	The VNT is changed and now is working in sync with the turbo, but we can't get performance from the car when it's working on normal temp. The last few weeks ware TOO hot here and the performance of the car was like the car has only 60hp not 160hp. This days the temp is lower and I've made a few videos wit the car is cold (starting it after a night getting cold) and when the car hot after driving for 1 hour. On this "when cold" video i could get even better performance but the road was not for fast driving, (i had to stop on 4000rpm in 3rd gear)but as you can see i can get to 5000rpm(2nd gear) which is not possible when the car is hot. [YOUTUBE]https://youtu.be/hKfyVCJaM-I[/YOUTUBE] This next video is when the car is driven for about 1 hour and the temperature outside is 22C (last few weeks was around 37-38 and the performance ware even worst). Here is when hot and as you can see the RPM's are loading slower and i had open road here and the pedal was pressed full. [YOUTUBE]https://youtu.be/LipXpLf1KUs[/YOUTUBE] I think it's something with rubber which is making performance issues when hot, but my mechanic think it's lack of fuel, because he checked for leaks and we don't have black smoke when pressing the pedal, also we have characteristics of not enough fuel on older disel cars., One of the first things we changed was the fuel pump which is in the fuel tank under the back seat, but the pump we got was from another car NOT NEW, the old one was just leaking and with this one we had some improvement but we think this is low pressure and we can't find not even in VIDA which the values should be. Please take a look at the video and tell me if this is OK: [YOUTUBE]https://youtu.be/IQCJNN27vSw[/YOUTUBE] At this moment we don't have a car with the same engine to compare but on citroen i think the car is not working if the fuel pump is not making 1.8bars and in our case we don't have even 0.1-0.2 bars, if you put a finger the fuel will stop. Any ideas before we spend out money on new fuel pump? Forgot to write we changed the fuel filter when we changed this pump and once again few weeks ago when we tried to clean the fuel system with blowing high pressure air from the engine to the filter and the other way around. Last edited by nstojanoski; Aug 14th, 2017 at 20:16.