Ford Transit: Power Loss at Operating Temperature

Hello everyone!
Bin mehr oder weniger aus Zufall auf diese Page getroffen. Excellent.

'Technically, I'm relatively new to the field of diesel engines. I come from a background of motorcycle mechanics (not just hobbyists; I know what piston ring clearance is). Nevertheless, please forgive any potential naiveté.'

Vehicle: Ford Transit, manufactured in 10/1998, 92,000 km mileage, 2.5L engine, 76 horsepower, naturally aspirated diesel engine (no criticism intended for my powerful machine!), Bosch mechanical ESP.

Here's the translation:

'The problem is this: The engine starts perfectly fine when cold, and you can clearly feel the power kicking in around 2,600 RPM. However, as the engine temperature increases, this threshold shifts upwards to around 3,300 RPM.'
At all temperatures, the vehicle easily revs up to 2,500 rpm.
Now for the strange part. When warm, it exhibits an acceleration of up to 3,200 RPM, but only for a few seconds. Then, the engine runs perfectly fine again.
Timing belt has been replaced, valves have been adjusted, and the oil has been changed.

Is the speed adjustment of the ESP stuck? If so, can it be fixed with readily available tools and materials (I have proper tools)? Does anyone have diagrams for the pump, adjustment mechanisms, etc.?

If it's not because of that, then what is it because of?

Hello Ralli,
After six months, I finally received a response, but it wasn't the right one.

I also happen to own a Transit van, manufactured in 1999, with 60,000 km on the odometer, and otherwise the same specifications.
'I've been experiencing similar issues with the engine performance for the past year. The Ford service department suggested that I disable the EGR valve, which I did, but it didn't solve the problem.'
In another forum, I was advised to clean the intake manifold.
Perhaps this will help.
I assume you've already fixed the problem or sold the car. Could you please let me know what helped?

Greetings.
R.J.

Hello R.J.

First, the negative: This will be expensive. The Bosch service costs approximately 1000 EUR all-inclusive (timing belt, tensioner, serpentine belt, installation...).

The tips about the AGR valve and intake manifold are nonsense. If the same problem exists as in my case, a performance loss of this magnitude cannot be explained in that way.

'The following issue occurred: My predecessor did not clean or replace the diesel filter. As a result, water entered the ESP (Electronic Stability Program) system. After a prolonged period of inactivity, the piston corroded and developed fine grooves. When the engine was cold, the tolerances were tight enough to build up sufficient pressure. However, as the temperature in the engine compartment increased, the injection pressure decreased, just enough that the vehicle accelerated minimally. If the virtual 'turbo lag' threshold was exceeded, the higher RPM in the ESP caused a hydraulic seal failure (hydraulic shock). Then, the vehicle would function properly again until the critical RPM (which increased with temperature) was reached.'
This type of error was already known to the Bosch service department for similar ESP systems used in other vehicles with a similar 1.6L diesel engine, such as the VW bus.

Habe den Wagen nicht verkauft, weil ich zu diesem Preis-Leistungs-Verhältnis nichts gleichwertiges bekomme. Der Händler hat die Reparatur zu 60% übernommen. Das war o.k. so. Sonst bin ich mit dem rollenden Wunder sehr zufrieden. Motorad, 2 Fahrräder und Gepäck für 2 Personen und 3 Wochen passen rein. Das wMy goal is ar.

Best regards and good luck.
Ralli.