Volvo 2.5 TDI: My Latin is at its end!

Hi,

I'm at my wit's end. My V70 TDI (2.5 Audi/VW 5-cylinder, 103 kW, 323,000 km) starts 'terribly.' The following parts have already been replaced:

ESP.
NHG.
Nozzles.
Coolant temperature sensor.
Fuses checked.

The glow plug and starter relays are the same. Swapping them didn't help either. The car starts poorly in the morning. I suspect the glow plugs aren't working.
Okay, so I took a spare glow plug that I had lying around, made sure it was in good condition, plugged it into the head, connected it to the power supply, and pre-heated it. It only got lukewarm during the pre-heating process, and that was at temperatures around 0 degrees Celsius.

Could it be related to the ESP settings?
Once it starts, it runs well. There's no water in the oil, and vice versa.

I read in a post that the V6 TDI has an electric pump in the tank to keep the chamber in the ESP system full. Does my V70 TDI have that too? I can't find anything like that.

I know, my contribution isn't exactly brimming with knowledge, but not everyone can be a genius!!

I would be grateful for any help!

Quote:

It was only lukewarm

.

"At temperatures below 5°C, it must glow. Check the temperature sensor on the engine to see if the control unit (ECU) thinks it's warmer than it actually is."
You can check the values without disassembly; simply use VAG-COM on a cold engine to verify the plausibility of the temperature readings in the engine control unit.

"But, in my opinion, it's all already covered in the technical article."

Thanks for the tip, but the coolant temperature sensor has already been replaced. Which other temperature sensor could be responsible, and where can I find it?
I have already looked into the technical articles.

PS: It seems that VAG-Com doesn't work with Volvos. Volvo uses a different software/protocol.

Quote:

It seems that VAG-Com doesn't work with Volvo. Volvo uses a different software/protocol

.
Oh, that's a shame, not even the motor control unit?

It would have been best to determine whether the correct part was swapped and whether it even made sense through the diagnosis.
It might be worthwhile to find a Volvo dealer who can read the engine control unit (ECU) and, with that capability, determine why the glow plugs might not be working or if there's any other underlying issue.
Otherwise, you'll just be trading places with death.

Best regards, Rainer.

My last visit to the Volvo dealer was a shock. The coolant temperature sensor was only replaced because it was damaged when disconnecting the plugs from the glow plugs (the plugs need to be pried off with a large screwdriver). As a result, I had to go back to have the part replaced. This, including clearing the error memory (a faulty sensor creates an entry), cost me over 95 euros in total. In addition, they managed to break the SRA motor in the headlights. The wiper wasn't in its starting position (which can happen), and the idiot who was swapping parts got the wiper stuck between the headlight and the hood. Now the wiper is completely ruined!
That's all about the Volvo dealer!

323,000 km

Was the compression ever measured?

No, the compression hasn't been measured yet. However, the engine pulls very well and starts immediately on the first turn when it's warm. Could there be a connection between these two things?

Hi,

Did the effect develop gradually, or was it more sudden?
Trying to adjust the pump slightly earlier would be worth a shot. -> Mark the exact position and rotate it slightly earlier. Make sure you can find the original position again.

Best regards, Rainer.

Hi,

Have you also checked the fuse for the glow plug system?
When the battery is nearly depleted, it can also cause the glow plugs to remain almost cold.
For diagnostic purposes, the connector for the temperature sensor can also be disconnected, in which case the engine should always be preheated.
When was the timing belt last changed?
Could the valve timing be slightly off?
My car also exhibited somewhat sluggish starting behavior when cold last winter (the timing belt was approximately 110,000 km old).
After the timing belt was replaced, it was working fine again, even though the pump had been precisely adjusted beforehand.

Best regards from Berlin.

Olli.

Which timing belt are you referring to? The belt for the water pump is new, and the two tensioners on the water pump side are also new. As I mentioned, the ESP (Electronic Stability Program) was replaced with a good used one. I'll double-check the fuses again. Although I've already checked the fuses, I should probably measure their resistance. I'll try adjusting the injection timing slightly earlier tomorrow morning and see what happens. The strange thing is that the preheating indicator light is on.
It's just incredibly frustrating. The Bosch service couldn't really help, the Volvo dealership is too expensive, and so on...
I've already spent 1000 euros on a used pump, including installation. Then I bought a set of used nozzles, then a new NHG (presumably a component), and so on.
The workshops are all just specialized in exchanging parts these days!

By the way, thank you for the many tips .

Hello,
Unfortunately, many workshops no longer master the art of proper troubleshooting.
Best regards,
Günther.

Perhaps there is someone here who is from Bavaria and can help me a little?

Hello,
Is it really preheating? If not, I would then try to find the error by 'working backwards.'
Best regards,
Günther.

Backwards??????

Backwards??????

Hello,
Okay, so if it doesn't preheat, check if there's voltage reaching the glow plugs; yes, glow plug is broken; no, fuse is blown; no, glow plug relay is broken or not being activated, etc. ........
So, you start somewhere where 'something' is missing, then you try to find the cause of that 'missing something' in the most logical way possible, and eventually, you'll find it.
If the engine only fails to start when it's cold, the glow plugs are a good place to start troubleshooting, along with checking the compression and ensuring the battery is fully charged.
'A lukewarm' glow plug is definitely not okay with the current temperatures! You should be able to burn your fingers quite badly; it's called a 'glow plug' for a reason!
Best regards,
Günther.