Diesel Engine Treatment

[skeeterm5]

Hi all

I have an old diesel truck and have just bought some STP engine cleaning products that you add to the fuel.

- injector cleaner
- dpf filter cleaner
- general fuel system cleaner

Question, can I add all three at once to the tank or should I do them one at a time to different tankfuls?

TIA

[Belle427]

I wouldn't mix them personally.

[Tony1963]

How old is the truck?

[stevieturbo]

late night drunken purchase, or is there some other reason for buying these things ?

[Demelitia]

Seems like theres a bit of overlap with the fuel system stuff.

Don’t stick them in all at once, and dilute them with the correct amount of fuel rather than running them over concentrated like some may suggest.
A good portion of the effectiveness of engine treatments is accounted for by the amount of time it sits in the engine, soaking and dissolving deposits in to fuel/oil to be taken away.

I’d put the DPF stuff in last; it seems like anything removed from the engine will end up there so makes sense to try get rid of it.

An oil change to get rid of any additive that’s made it to the sump wouldn’t hurt.

[stevieturbo]

And will an "old diesel truck" even have a DPF ?

[skeeterm5]

Thanks all.

It is 2003, and I bought a set of the 3 STP cleaners because they were on offer for the price of just the injector cleaner.

The truck is a little hard to start when cold, I have already replaced the glowplug circuit and the fuel filter. Next job will be replacing the actual glow,plugs. But I thought it would hurt to run some cleaner through the internals, hence the stuff.

Now the plan is to run the general fuel system cleaner through and then the injector cleaner.

[stevieturbo]

Have you tested the glow plugs to see if they need replaced ?

[skeeterm5]

That’s my next step, and then replace if necessary.

Symptoms are cranking for a long time when cold, white smoke from the exhaust which I think is unburnt fuel, and then it finally starts.

Once warm it starts first crank.

If the glow plugs isn’t the issue with cold starting then I guess it is more serious as I will then have checked/replaced all of the starting components.

[Belle427]

Always worth changing them first if they are fairly easy to get at.

[stevieturbo]

Belle427 said:

Always worth changing them first if they are fairly easy to get at.

Always worth testing, to save wasting time/money

[skeeterm5]

To close off.

I ended up replacing the glow plugs, cleaned the buzz bar and replaced the glow plug relay. It now starts on the first turn of the key.

Thanks everybody for comments.