Ad Blu in a petrol car !!!

[Monty1502]

A friend of mine lives abroad, he has two Mercedes - a diesel estate and a petrol 400 SL -

For some bizarre, unfathomable reason/ senior moment etc , at the weekend after topping up the Ad blu in the diesel estate he " decided to put the surplus in the ( petrol tank of the ) other car " !! ( i.e petrol 400SL ) - after driving around four miles in it, unsurprisingly it conked out and he phoned whatever the Spanish equivalent of the AA is called, who recovered the car and took it to a Mercedes main dealer. I spoke with him today and the garage " are going to get round to looking at it this week "

To put him out of his misery does anyone have any idea of the damage that may have been done ? Is it something that can be rectified by some sort of "engine flush " ? or is he completely screwed and it'll need a new engine ?

I've never actually owned a diesel so have absolutely no idea on the subject ( other than the fact that he should be locked up for his own safety !

Any advice / ideas welcome.

[Monkeylegend]

Can be quite corrosive to fuel lines and engine internals apparently, so needs to be drained and flushed through as soon as possible.

[and31]

I’m going to say the damage could be significant-

[Road2Ruin]

Ad blu has a separate tank, it does not go in with the fuel! So it is more than a senior moment. I would be amazed if it did any damage. It is basically urea, so probably just ran out of 'fuel' to burn.

[SAS Tom]

Never heard of someone doing it so would say it’s somewhere in between it’s fine or the engine is dead.

The two things that come to mind for me are, it just needs petrol in it or it could have hydrolocked the engine and bent a rod.

[Austin Prefect]

Do you know how much Ad Blu ended up in the petrol car, and how much petrol was in it?

[and31]

It’s corrosive-adblue tanks are plastic for a reason

[Monty1502]

Austin Prefect said:

Do you know how much Ad Blu ended up in the petrol car, and how much petrol was in it?

I think the SL had around a quarter of a tank of petrol and he added around 3 -4 litres of Ad blu !!!!

[Richard-D]

My money is on it being fine. He will need to drain the tank though and purge the fuel system.

Adblue is far heavier than petrol so it will have gone straight to the bottom (where the pickup is).

[Nicks90]

I think he might be in for a rough bill.
Ad blu is heavier than petrol, so it will have squirted a very high concentration in to the cylinders, where it wont have burnt and could have a) built up in the cylinders and partially hydro'd the engine b) leaked down and contaminated the oil c) caused damage to injectors and fuel pump

Best case, fuel system flush and oil change + all relevant filters at a minimum and hope for the best.
At worst, new engine.

[Yahonza]

There will damage to the fuel system from the water but also from the urea in the additive.
Could be nasty cost wise.

[Caddyshack]

Nicks90 said:

I think he might be in for a rough bill.
Ad blu is heavier than petrol, so it will have squirted a very high concentration in to the cylinders, where it wont have burnt and could have a) built up in the cylinders and partially hydro'd the engine b) leaked down and contaminated the oil c) caused damage to injectors and fuel pump

Best case, fuel system flush and oil change + all relevant filters at a minimum and hope for the best.
At worst, new engine.

If they poured what they had left from
A barrel in to the tank then surely that would be maybe a litre? I would have thought some would have steamed as soon as it hit the hot pistons and would you get enough in to the cylinders to hydro the engine? I am guessing it will be blocked filters, pump and a good flush but interested to know.

I have heard of people using water injected to clean engines and water injection to cool intakes.