Put Petrol in a Diesel Lancia Thesis by Mistake?
Anyone who has put petrol in a diesel Lancia Thesis without running the engine ought to leave it switched off, and not start it even to roll it away from the pump. Draining your tank is usually enough to put your Thesis right, provided the petrol stays in your tank, which it will whilst your motor is off.
We come to misfuelled vehicles rather than the other way round, so with Petrol in Diesel your Lancia Thesis remains on the forecourt or wherever it has stopped. Hold off attempting anything yourself until you have rung us, and we'll explain what to do.
The first steps with petrol in a diesel Thesis
- Do not start the engine, even though a diesel Thesis will normally run with petrol inside the tank. It can feel normal for a time, and that is how motorists often pull away without realising something is amiss.
- Your ignition has to remain off as well, since turning it on starts the fuel pump priming on a lot of diesels, and your pump then draws fuel out of the tank.
- Filling up with diesel to dilute it is a bad idea, even with super unleaded, which is petrol as well. The tank in the Thesis takes up to 75 litres, and every litre of diesel put in is more tainted fuel for us to empty.
- A vehicle in the way of a pump can be popped in neutral and pushed clear, and the forecourt staff are usually glad to help.
- When the badge shows the exact version, for instance the Thesis 2.4 JTD 20V, mention it once you call 0333 366 0103. Tell us too which Thesis you drive and where it is parked, roughly how much petrol was put in and whether the engine has run.
Wrong fuel in your Lancia Thesis once the motor has run
The motor is not touched by wrong fuel in your Lancia Thesis till it's pulled out of your tank, and starting your engine is what draws it out. In a diesel engine, the fuel lubricates the injectors and the injection pump on its way through. Driving any distance on that mixture is what can do damage, since petrol thins the diesel and strips that lubrication away.
If you have driven the Thesis on it, the right thing to do is pull over in a safe place then switch your motor off. We can still put it right, by draining the tank and flushing the lines and your filter till all of the tainted fuel is out. Very few vehicles that are caught soon and cleaned out thoroughly end up with permanent damage.
It is the same whatever version of the Thesis you drive, and that includes the Thesis 2.4 JTD.
The fuel tank capacity of the Lancia Thesis
If you filled up when your tank was nearly empty, the same couple of litres make up more of your fuel in it, and the risk hinges on that share, which means the capacity of the tank counts.
In our figures, all of the diesel versions of the Lancia Thesis share one tank of 75 litres, so the sum works out the same for each.
| Version | Fuel tank |
|---|---|
| Lancia Thesis 2.4 JTD | 75 litres |
| Lancia Thesis 2.4 JTD 20V | 75 litres |
| Lancia Thesis 2.4 Multijet 20V | 75 litres |
Telling which diesel Thesis you drive
The version is normally on a badge on the boot lid, and it's useful for us to know when you ring.
On your diesel Thesis, the badging found is JTD and Multijet.
The JTD badge is the most common in our records, but the Thesis 2.4 Multijet 20V is badged Multijet.
Each variant in our list has a motor of 2.4 litres.
AdBlue in a diesel Lancia Thesis
Certain diesel cars carry a mix of water and urea, called AdBlue, in a tank of its own with a separate filler, and rely on it to clean up their exhaust. The key should remain out of your ignition if you've got AdBlue in a diesel Lancia Thesis through the wrong filler, and that includes moving your car.
As it is mostly water, AdBlue doesn't burn and gives the fuel pump no lubrication whatsoever. It doesn't mix with diesel either, so it settles to the base of your tank where your pump picks up its fuel, and a tank of up to 75 litres does nothing to dilute it the way it would dilute petrol.
However small the amount, some of that is pulled into the line. When the water has evaporated, what's left is urea, which forms crystals inside your fuel system, filter and injectors among them, and attacks any metalwork it touches.
The same filler flap frequently hides both fillers, and where your Thesis has an AdBlue filler, it may well be next to the diesel one. AdBlue caps are usually blue and accept a far narrower nozzle than diesel.
How a fuel drain on your Lancia Thesis works
Moving your vehicle to a garage isn't needed, as a fuel drain on your Lancia Thesis is done right at your vehicle. To begin with we find out what was put in and whether the engine has been run. The tank, which holds up to 75 litres on the Thesis, is then drained, the lines and filter are rinsed, and the car is refilled with fresh diesel and primed before we start the car.
Once the job is done, your Thesis runs on fresh diesel and you can carry on.
What AdBlue removal from a diesel Lancia Thesis means
The steps are the same as draining petrol in AdBlue removal from a diesel Lancia Thesis. AdBlue gathers at the base of the tank instead of blending in, and if the Thesis has been run it may leave crystals in the pipes, so we rinse those out too and change the filter if it needs it.
AdBlue removal here means getting AdBlue out of your diesel tank after it has gone into the incorrect filler. It does not mean removing or disabling the AdBlue system on the vehicle.
How much does a fuel drain on the Lancia Thesis cost?
The work differs from one job to the next, so we do not publish a fixed quote. The main factors that shape it are these:
- whether anybody has started or driven the Thesis, the thing that counts most
- a tank's capacity next to the amount that was put in
- what went in, petrol or AdBlue
- whether the van can easily and safely reach the Thesis where it is
With those details over the phone, we can let you know what the job is likely to involve.
Queries about petrol in a diesel Lancia Thesis
Your Lancia Thesis fuel tank capacity: how many litres?
All the variants we have data for take 75 litres.
Is it all right to add diesel after just a little petrol in my Thesis?
Topping up just lowers the proportion of petrol. None of that is taken out, so it's all still there when you drive off, which is why we wouldn't recommend it. A drain gets all of it out, and with a modest quantity that is usually all your Thesis requires.
Do I need to take my Thesis to the Lancia dealer?
There's no reason to move it anywhere. We empty and clean your Thesis where it has stopped, and we are independent, with no link to Lancia or any of its dealers.
Does it help to know which Thesis I have?
Yes, it helps. Our figures cover 3 diesel variants of the Thesis, so tell us which one you have when you phone.
Is wrong fuel in my Lancia Thesis covered by my policy?
It is worth checking your policy, as misfuelling cover is part of some but not all. Whichever way it reads, we come out and empty your car.
What should I do if my Thesis got diesel in its AdBlue tank?
In that case, too, leave your key out of your ignition. If it is driven like that, a car will normally show an alert and go into limp mode. The AdBlue system needs draining too. When you phone, tell us which tank your fuel went into.
I have already driven my Thesis. What should I do?
Until we get to you, your motor needs to remain off, so pull over where it is safe and turn it off. We drain and clean the system where you have stopped, and when it's caught early like this, long-term damage is very rare.