SEAT Leon - No coolant and heater issues

[Pulse]

Hoping someone can give some quick insight before my friend calls the dealer.

A friend of mine has just bought a 2013 SEAT Leon, 2.0TDI if that helps, and on the way home eprom the dealer yesterday, it threw up a message saying the coolant was low.

When he got it back, it wasn't just low, it was non-existant! Since then, he's also noticed that the heater only gets to 'warm' and after a while stops providing warm or hot air at all.

My initial thought was... Well, that's just not good! You don't just lose coolant unless there's a leak of some sort or a head gasket has gone, do you? Not sure on the heater though, or if it's linked.

Any advice appreciated!

[shavermcspud]

Could be a leakey heater matrix, they are both linked, the coolant from the engine passes through the heater matrix to provide hot air in the cabin.

You should be able to identify if the head gasket has gone.
What happens after the coolant is topped up, engine left running, do you see any leaks or smoke from the exhaust.

[lord trumpton]

As said above the heater behaviour is entirely related to the low coolant. As you have lost coolant then there is a leak of sorts and if there is a leak then not only can water escape but air can intrude into the cooling system. The erratic heater operation is explained by hot coolant passing through the matrix and giving heat and then going cold as air passes through.

The next step is to find out where the water has escaped from - leaking hose, leaking heater matrix (should smell inside cabin if so) Leaking filler cap, leaking radiator etc

HGF can be tested using a sniffer test - this detects hydrocarbons in the coolant from exhaust gasses. It's a kit that can be easily bought if you fancy having a go yourself.

Leak detection can be tricky due to access - Ring automotive do a kit that has a UV dye that you add into the coolant and a UV torch that you use to scan the engine bay for UV leakage (it glows green)

Whatever you decide, the system needs refilling and bleeding before driving - I would take it to a garage and have them test the car out. Coolant leaks and system checks are bread and butter stuff for a decent garage

[battered]

Just bought you say? Take it back, it's faulty. 3 yr old cars don't lose coolant. If the heater is leaking you will have wet carpets and steamy cabin, if radiator then it will leave puddles, if HG then you will see steam in the exhaust and smell antifreeze.

[DanSkoda]

It's relatively common for that engine to have a leaking water pump or a failed EGR cooler which would create the symptoms your friend is experiencing.

[Pulse]

Thanks everyone for your quick replies. Just as I thought, coolant doesn't just disappear. Sadly.

Glad in a way that they are linked, since that will hopefully help diagnose the issue and the dealer can't have any issues taking it back (whereas he may have just said to fill up the coolant otherwise).

It has a 3 month warranty, so my friend is speaking to them when they open. Would you advise he doesn't drive it, especially given he probably drove it without coolant for a few miles? I can imagine the dealer will want him to drive it back (around 60 miles).

[lord trumpton]

Pulse said:

Thanks everyone for your quick replies. Just as I thought, coolant doesn't just disappear. Sadly.

Glad in a way that they are linked, since that will hopefully help diagnose the issue and the dealer can't have any issues taking it back (whereas he may have just said to fill up the coolant otherwise).

It has a 3 month warranty, so my friend is speaking to them when they open. Would you advise he doesn't drive it, especially given he probably drove it without coolant for a few miles? I can imagine the dealer will want him to drive it back (around 60 miles).

No do not drive it. Asking for trouble.

You should insist the dealer recovers it

[steveo3002]

can imagine its done some more damage driving it with no coolant , be lucky if it hasnt

[TooMany2cvs]

Pulse said:

A friend of mine has just bought a 2013 SEAT Leon, 2.0TDI if that helps, and on the way home eprom the dealer yesterday, it threw up a message saying the coolant was low.

And he continued driving it, without checking?

How far had he driven before the level warning came on? It's entirely possible other traffic threw a stone or something up which punctured the rad. If that's the case, then that's not something the supplier is in any way responsible for - just as if the stone had taken a headlight or the windscreen out. Any damage arising from continuing to drive would also be his problem, even if the loss of coolant was due to a mechanical problem that the dealer would be responsible for.

Failing to stop is failing to take foreseeable steps to mitigate the losses.

[anonymous-user]

Just because the coolant got low doesn't mean the car overheated, as long as that didn't happen then no harm done.

[TooMany2cvs]

charltjr said:

Just because the coolant got low doesn't mean the car overheated, as long as that didn't happen then no harm done.

The header tank was bone dry, and the heater had stopped putting out any heat.

There's almost certain to be issues arising from running it that low.

[benjijames28]

TooMany2cvs said:

The header tank was bone dry, and the heater had stopped putting out any heat.

There's almost certain to be issues arising from running it that low.

What kind of issues would u expect?

[battered]

TooMany2cvs said:

And he continued driving it, without checking?

It said low coolant, not "stop the car". Any car made in the last 20 years has a system of rising hysteria when it comes to warning lights.

OP, your friend needs to ring the dealer ASAP and they must collect the car. DO NOT drive it. Make it very clear to them that you stopped and checked the coolant as soon as you arrived home and it was safe to do so and that it's lost a lot of coolant, and that you don't want to risk damaging the car, so they must collect it.

As for "a stone could have done this", well, yes. It's possible. It's also possible that the moon landings are fake. In about half as million miles of driving I have been hit by a great many stones, none have damaged a radiator to the point where it lost all its coolant in one drive. I've never heard of it happening to anyone else either. Apart from anything else it would do well to get past the grille, and if he'd hit anything that hard then he would have noticed. So, possible, yes. Likely? No.

Now let's look at the more likely scenario. The thing was almost certainly faulty at the point of sale. The likely scenario is that the previous owner had a fault, I'm guessing the head gasket, didn't like the bill and so threw in a bottle of K-Seal and tiptoed round to the dealer in it to get rid. Dealer has given it a nob-up and not tested it, the fault has recurred on your pal's way home.

I have a lot of sympathy for dealers who must get sewn up a lot on this sort of thing, but if they don't check then they should. Maybe they are making enough on the tradein to take the occasional bath, so they don't need to look too hard, and I know that they are happy to punt the things out of the door and let the new owner report any faults.

[lord trumpton]

battered said:

TooMany2cvs said:

And he continued driving it, without checking?

It said low coolant, not "stop the car". Any car made in the last 20 years has a system of rising hysteria when it comes to warning lights.

OP, your friend needs to ring the dealer ASAP and they must collect the car. DO NOT drive it. Make it very clear to them that you stopped and checked the coolant as soon as you arrived home and it was safe to do so and that it's lost a lot of coolant, and that you don't want to risk damaging the car, so they must collect it.

As for "a stone could have done this", well, yes. It's possible. It's also possible that the moon landings are fake. In about half as million miles of driving I have been hit by a great many stones, none have damaged a radiator to the point where it lost all its coolant in one drive. I've never heard of it happening to anyone else either. Apart from anything else it would do well to get past the grille, and if he'd hit anything that hard then he would have noticed. So, possible, yes. Likely? No.

Now let's look at the more likely scenario. The thing was almost certainly faulty at the point of sale. The likely scenario is that the previous owner had a fault, I'm guessing the head gasket, didn't like the bill and so threw in a bottle of K-Seal and tiptoed round to the dealer in it to get rid. Dealer has given it a nob-up and not tested it, the fault has recurred on your pal's way home.

I have a lot of sympathy for dealers who must get sewn up a lot on this sort of thing, but if they don't check then they should. Maybe they are making enough on the tradein to take the occasional bath, so they don't need to look too hard, and I know that they are happy to punt the things out of the door and let the new owner report any faults.

I'd be surprised if it was HGF at that age of car unless it's been to the moon and back. It's quite uncommon these days; especially on those iron block diesels.

I'd go with a leak somewhere but like everything on the net when it comes to fault diagnosis - it's just conjecture

[Pulse]

Thanks all for your help. As it turns out, he doesn't need to take it back to the dealer - it is still covered by SEAT warranty.

It's now with SEAT and being looked at this week. I'll report back on the findings.

[AlexIT]

Just FYI I had the same when mine was a couple months old (2.0 TDI as well).

No sign of leakage anywhere to be seen neither on the driveway or on the company car park. I brought the car to SEAT and they said that it was probably due to a bubble in the cooling system (yeah... after a few months and several thousand kms...).
Whatever the actual reason was, it was rectified and more than a year and 40.000 Kms after it's been flawless.

I'm curious as what Seat will tell you.

[Pulse]

shavermcspud said:

Could be a leakey heater matrix

It was!

It's had the heater matrix and the water pump replaced.

[anothernameitist]

Glad its sorted, but why in summer would you need warm air in the car?

[Pulse]

anothernameitist said:

Glad its sorted, but why in summer would you need warm air in the car?

Pass. I imagine he was then (having already found something wrong) testing everything else to make sure it worked.

Good thing he did, as they ended up linked and I'm sure it'll have made diagnosis easier.

[bbuck321]

Hi i need help.
my seat leon 1.6, petrol, came up with a warning light on the temperature gauge last night although i had topped it up earlier that day. when i went to it this morning the coolant was completely empty, and had leaked on the floor. i have since topped it back up with coolant and have solved this issue. but now there is an odd knocking sound coming from the engine which i cannot identify. is there a correlation between the lnocking sound and the lack of coolant last night.