Exhaust Smells Like Water: Troubleshooting Guide

Hello forum,
For 3 days now, my exhaust (1.9L TDI ASZ) sometimes smells like "something inside the coolant reservoir," meaning it smells exactly like putting your nose in there and taking a breath .
It smells more like a laundry room than exhaust fumes.
I noticed this very clearly once before, and I've seen a milder version of it again today.
So far, nothing is missing from the coolant reservoir.
There's no grime or dirt on the oil filler cap either.

Being alone right now wouldn't have bothered me as much, but I've also been having trouble starting up [something] since yesterday, although it wasn't happening this morning.
It's possible that the simultaneous occurrence of these two symptoms, a smell and starting problems, is not coincidental and may be related.
Otherwise, the engine runs normally and smoothly, with the usual powerful sound.

I checked the error memory, the plausibility of the coolant temperature value, and this morning, the current draw of the glow plugs.
Everything seems to be perfectly normal.
Yesterday, I also filled up with branded gasoline because I suspected that the problem might be due to low-quality fuel.

What do you think about that?
Has anyone else experienced something similar?

Best regards,
Jörg

As long as no coolant is being used, none can enter the exhaust system.

I would mark the coolant level when the engine is cold and observe it for a while.

I have it in mind, but nothing is missing so far.
Earlier, white smoke came out of the exhaust, and the road surface underneath became wet. There's definitely water coming out, but only intermittently.
After I drove away with my camper and started moving, it was really intense for a moment, but it only lasted briefly, and then everything was fine again.
I've heard about bad fuel before, but I've never had any problems with it myself.
I'm currently leaning towards fuel as the primary cause.
Let's start with the simplest option, although with my mileage, I also have to factor in the possibility of engine damage, unfortunately.

Best regards,
Jörg

Is this happening with a cold or a warm engine?
hg
Herbert.

When it started poorly, both with a cold and a warm engine.
So far, I have only smelled or seen white smoke and a burning smell when the engine is warm.
However, I cannot rule out the possibility that this also occurs with a cold engine.
As I said, I've only been experiencing these problems for the past 3 days, and it's too dark in the morning to see much.
Could it be that water has accumulated in the tank over time, and that the system occasionally sucks up this water? That's a theory that's been on my mind lately. I'm going to check the search function again about this right away.
Best regards,
Jörg

White smoke from a warm engine is most likely due to the evaporation of water. This points towards a blown head gasket. The smell also fits this. Are you sure it doesn't smell acrid like poorly combusted diesel?
Water drawn from the tank would be separated in the diesel filter. Although it doesn't quite fit the observed symptoms, have you drained it recently?
hg
Herbert.

Yes, I drained it, meaning I estimated the amount at the bottom, about half a shot glass, and poured it onto a cloth. I can't really say if there was a significant amount of water in there. It definitely smelled like diesel fuel.

I'll believe it's a blown head gasket when I clearly see that coolant is missing. Right now, there's no coolant loss.
If the diesel fuel is not burning properly, the smoke should tend to be bluish, grayish, or black, right?

Just now, while searching, I found something else: if there's water in the tank, add some alcohol to the tank, which will then mix with the water.
This is how the water, if there is any, is supposed to come out of the tank.
Is that a common practice? I'm a little worried about lubricating the PD elements.
Best regards,
Jörg

Quote:

This is how the water, if there is any water, is supposed to come out of the tank.

How?
To drain the diesel filter, you typically use a container, such as a glass, that can hold about 100 cubic centimeters. This allows you to see if any water was present in the filter.

Quote:

If the diesel fuel is not burning properly, the smoke should tend to be more blue, gray, or black, right?

Blue or black, depending on whether it was injected poorly or if there's too much product.
The cause is not entirely clear. You should be aware that if it's a head gasket issue, the problem could quickly escalate. I wouldn't recommend taking any more long trips with the caravan until the issue is investigated.
hg
Herbert.

I had already suspected that the dehydration process wasn't ideal. That's why I described it in more detail, so that there might be some constructive criticism of my approach }.
I'll try again tomorrow and drain it into a container.
The WoWa is now in hibernation and won't be moved anytime soon.

Best regards,
Jörg

I'm almost disappointed now.

Heute morgen ist er einwandfrei angesprungen, kein Weißrauch und kein Tropfen Wasser im Oelfilter. Everything is normal.

So, my theory about water being in the diesel is starting to seem less likely.
I just checked the Lufi box, and it's okay too.

If I come to any further conclusions, I will let you know.
Best regards,
Jörg

Hello again,

I think I might have tricked myself with the "smell of water and exhaust fumes."
In addition to that, there was the problem of the engine being difficult to start, which disappeared after refueling.
I think the exhaust smells different because there was a lot of diesel fuel in the oil.
I checked the oil level today, and it was about 1 cm above the maximum mark.

I just changed the oil, so now I need to monitor the situation and see how it goes.
And another thing I don't understand. The engine always starts poorly when the tank is only a third full. I tried that yesterday for the third time. That can't be a coincidence.
With over 425,000 kilometers on the clock, it's not surprising that an engine might wear out. However, I'm not ready to give up just yet. It might still be possible to carry out a cost-effective repair. I'm not really in the mood for buying a new car.

Considering that the corrosive fumes started at the same time as the poor starting performance when the tank is empty (below 1/3 full) and the increased oil consumption, I wonder what the underlying cause might be. Could it be a leak in the cylinder head leading to a problem with the glow plug element?
Best regards,
Jörg

Quote:

Could a leak in the cylinder head be related to a PD element?

Possible... and possibly, due to the lower pressure difference with a full tank, without any effect.

I could also imagine that when the tank is empty, a minimal amount of air is drawn into the system from there, which may settle in the crankcase filter and, during longer periods of inactivity, enter the cylinder head.

You should definitely take a close look at the piping system to check for any damage.
Kr- Filter ist dicht? Possibly replace.

A few details about the vehicle would also be appreciated .

Quote:

A few details about the vehicle would also be appreciated. icon_wink.gif

Is it in the first post in this thread ?
Here's a more detailed explanation:

Seat Ibiza 1.9 TDI 96kW ASZ, year 2003.

Quote:

Is the Kr- filter tight? If not, replace it.

I definitely don't smell any diesel.

jörg schmidt wrote:

Hello again, And another thing I don't understand. The engine always starts poorly when the tank is only a third full. I tried that yesterday for the third time. That can't be a coincidence. With over 425,000 kilometers on the clock, it's not surprising that an engine might wear out. However, I'm not ready to give up just yet. It might still be possible to carry out a cost-effective repair. I'm not really in the mood for buying a new car. Best regards, Jörg

Hello!

Here are a few thoughts based on my experience, which might help with starting problems when the fuel tank is relatively empty:
e.g., from the Golf 2.

The problem occurred in some diesel and gasoline engines.

Apparently, in the diesel engines, when the tank was empty, the return flow was entering the tank in the "air" space, rather than into the diesel itself.
If a valve in the distributor injection pump was leaking, or if the return lines were not functioning correctly.
After several days, the ESP ran out of material.
That meant the startup process took quite a while.
The emergency solution was a check valve in the fuel line, which surprisingly worked for a long time.

"Something similar used to happen with gasoline engines, and it was due to issues with the fuel tank components."
It includes the unit with the fuel gauge and pre-pump, depending on the model.
It was made of cheap, molded plastic and sealed with rubber bands.
And if the fuel level was below the rubber rings, as I suspect, then air must have been drawn in there.
I've completely replaced the fuel sender pump assembly several times.
Then it started working again.

Hi,
I'm still trying to combine all three errors into one.
Smoke, oil leakage, starting problems.
For example, defective O-rings on the PD elements. But can they really break down that easily?
As a layman, I have no experience in that area.
Most likely, the head would also be damaged, and then a repair would be uneconomical.
Perhaps it's all just coincidence, and there are multiple causes.

Quote:

I have completely replaced the fuel sender pump assembly several times. Then it started again.

According to the VAG self-study program 209, this is a 1.9-liter TDI engine with a common rail injection system.
"There's no pump in the tank, just lines for the supply and return. That's why I've always thought it's unlikely that a line has a crack. However, I also hear a brief hissing sound from the tank when I turn the ignition key, which suggests there's an electric pump. But then there should be enough fuel to start the engine, right? The tandem pump only starts working when the engine is running."
Does anyone have an AKTE exploded diagram of the components inside the fuel tank?
According to the self-study program, a check valve is located in the suction line. Where exactly is it located?
Thank you in advance for your help.
However, the starting problem is my least concern; when the engine is on the verge of failure, troubleshooting the fuel system alone is essentially pointless.

Best regards,
Jörg

The title of the thread doesn't really fit anymore.

Sure, here's the translation:

"It's all messed up."

Today I spoke with a motor repair specialist who said that the PD-
The components may be leaking. Re-sealing required: €300 plus VAT plus valve cover.

A mechanic from Seat suggested it might be the tandem pump, which would cost 400 euros.
I think it's excessive to do all of that for troubleshooting.
It could also be the cylinder head, piston rings, or oil scraper rings.
So, a replacement engine? With 425,000 km on the clock? Probably not.
My heart aches. I will deeply miss my faithful Ibiza.
We've been through a lot together.
Tonight, I ordered a new one.

I hope that it will be at least as reliable and exactly as useful.
It's fun.
Best regards,
Jörg