Water pump and thermostat replacement recommendations and best practises for a 2016 Polo

[ciclo]

Take a look at this video, on your Polo 6c 1.2tsi 2016 the auxiliary belt has a very similar configuration.
https://www.youtube.com/watch?v=EcS3qqJ_wCY&t=199s

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Don't forget to read the first comment below the video.

[R826583]

Haha I see you there!

Thanks for explaining the different bearing locations.

I will try ciclo’s water spray method on the belt and have a hunt around the various accessories later today.

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On an unrelated note, I see that some people disable the stop-start system with either the voltage or temperature method. I am thinking about doing this… but I’m worried that giving the car a false threshold might cause it to charge the battery differently. Is the stop-start control logic different from the battery control logic?

[RUM4MO]

My way of looking at this is, by disabling auto Stop/Start, all you are doing is allowing the battery to always be in a better state of charge than it would otherwise be if auto Stop/Start was enabled - along with less "wear" on the battery starter motor and flywheel starter motor ring gear.

Now, if you have an EFB then you will probably be allowing the battery to stay useful for longer if you own that car for an extended period, if you have an AGM battery then not so much of a benefit as it has been shown that AGMs last for many more "start cycles" - I think that you could find a comparison online that compares FLA, EFB and AGM (fleece) battery starting cycles lifetime, if that interests you.

For some reason - maybe just because I could, I bought a cheap plug-in 12V DVM and so I can keep an eye on charging, this can be sort of interesting as I've discovered that some times when I drive economically/smoothly, with smart charging completely enabled, that the battery will be just in "survival" mode and never be in a good enough condition to allow auto Stop/Start to "happen", though during "normal" driving, that will never happen - that sort of surprised me, and explained why, at times, or just under certain conditions, even with an EFB or AGM battery thought to be in "good health", auto Stop/Start will not get enabled. That just means that under certain driving conditions, the battery's "store" stored charge will get used or harvested by the car's systems as the car is never in "regenerative brake" mode, when that source of stored charge has been used up, the alternator will then be providing charge/current to supply all the car's running electrical systems - and no more, ie maximum efficiency and minimum emissions.

Note:- when my wife's 2015 VW Polo 1.2TSI 110PS was just under 3 years old, and after it had been in the VW dealership for warranty work - replacing the gearbox mounting from the standard petrol engine version to the TDI version, to stop unwanted/undesirable transmission shunting ON/OFF throttle at low speeds, I eventually noticed that auto Stop/Start, which in Summer time I tend to leave enabled, just was not happening! So, one day after parking that car back in my garage, I lifted the bonnet and discovered that the BMS plug/lead was not connected to the battery -VE post, no doubt something that the VW dealership workshop had removed to get access to the gearbox (top) mounting, and forgot to fit back on, after that, auto Stop/Start working as expected - if allowed to by me.

[R826583]

I haven’t quite got there looking at the mysterious auxiliary belt whine… but I’m hoping to do that tomorrow.

That makes sense re the stop start system. I have noticed the little module thing connected to the negative terminal on the battery. I’m going to stick with clicking the ISS disable button each time I start the car, for now. I sometimes forget and go AHH what’s going on (!) when the engine shuts off, but it’s generally not a worry to disable upon startup. I’ve just been tempted to looking into disabling it with coding… but I’d rather leave it and finish dealing with my mysterious whining sound first My battery is an ISS rated AGM battery, so it shouldn’t wear it down but I don’t like the wear on the costly engine components. Interestingly when I coded the battery it was called “Fleece (AGM)”. Is “Fleece” another name for an AGM battery? From Googling it looks to be.

Another thing that I want to fix is my hand break has A LOT of side-to-side movement when in the down position. I’ll make a new post for this.

[RUM4MO]

I think that "fleece" is another name for an AGM that is a FLA replacement or even an EFB drop in replacement, there are many other versions of AGM it seems, including the AGMs built purely for compact performance - which tend to have differing charging requirements.

Even my CTEK smart chargers with a AGM mode, make it clear that that mode is for "other" versions of AGM batteries, and not these AGM ones we have, or can have.

[R826583]

Ah ok that makes sense why it was called “fleece”.

I’ve been out to look at the engine whining and I am fairly certain that the noise is coming from the serpentine belt or an auxiliary component that it is driving. I have sprayed a decent amount of water on the underside of the serpentine belt but this hasn’t stopped the whining. From doing some research the tensioner seems to fail often, so this could be making the whining noise. An interesting note is that when I turn on my AC it makes a buzzing sound clearly different from the whining sound when the AC is off (I assume the cause of the buzz is part of the Sanden compressor failures). Where do I go from here?

There appears to me to be the option of:
- the compressor bearing is failing (causing the whining noise… and the buzz coming from the compressor is some other failing part in it).
- the tensioner bearing is failing.
- the alternator bearing is failing.

SO MANY options… what is my next step in determining the culprit? Perhaps I have to remove the serpentine belt and give the shafts on the auxiliary components a wobble with my hand to see if there is any play. Another option would be one of those mechanic listing sticks that you push against a component and it magnifies the noise… which I could use to track the failing component down. What would you guys do?

[R826583]

Something else I have just noticed… there appears to be a rhythmic slapping coming from around the same area that the serpentine/auxiliary whining is coming from. It seems pretty in sync (as in the duration between the TA TA TA TA noises) with the serpentine belt

[R826583]

THIS video: https://m.youtube.com/watch?v=BZ5SGBOa3_0

At approx. 30s it captures the TA TA TA slapping noise I’m talking about. He fixed it by replacing the serpentine belt.

The whining noise also exists like usual. My theory is that the belt is failing and it creating the whining noise and the slapping noise. Regarding the AC buzz, I think it’s just the Sanden compressor failing - but it’s unrelated to the whining noise which is caused by the belt.

Just to clarify, I have three noises:
- Slapping noise (TA TA TA - only discovered today).
- Whining noise (discovered yesterday and what I’m referring to in all previously posts before the last).
- Buzzing noise (only existent when the AC is in - my hypothesis is that it is from the Sanden compressors that are known to fail - discovered a month ago but I just mentioned it for the first time in the latter post).

[R826583]

Any thoughts guys?

It’s looking like replacing the serpentine belt is the go to first step.

[Le_Combattant]

Buzzing soundz coming from Sanden compressor is common.

I have the same on my car. Still making ice during summer.
Last year I ask for a check up. Only 40gr of gas/oil were missing.

For a 10 years car it's good.

[2fast4ya]

I have done this replacement on my 2016 polo 1.8 gti tsi bm,
It was a bit of a mission at some points in the proceedure, with the gti there was a reasonable amount of bits to remove to actually get to see where the bolts were on the waterpump & actually get the thing off the engine lol good thing about the waterpumps on these polos is that everything is on the waterpump & not scattered about the engine, thats why the pump costs near on £300 , i bit the bullet & got the latest revised pump from vw dealer as i felt it better than getting an aftermarket one which may fail quicker.
I wanted to document the job but got tooo engrossed in doing the replacement to take pics or vids .
Some people take the air intake manifold off but i didnt so the space to do the job was bit restricted unfortunatly.
Lining up the pump to the bolt holes & blindly bolting it on whilst keeping the tiny belt & union pipe inplace was the worst bit of the job by far
Got it all back together & had a tiny leak which was coming from the union pipe in the oil cooler side so had to take it all off again to get that pipe seated properly , were supposed to vacume test before putting everything else back but i didnt as it was gettin late ! Like midnight late haha
Corrected it nxt morning , now ive effectively done that job twice in two days i reckon that it would take me half a day or less to do it again if i need to .

[R826583]

Good to hear that the job went well for you in the end

Let’s both hope that VW has updated their lasted pump design such that it doesn’t fail prematurely again.

[2fast4ya]

Yeah sorry been away for a while so havnt been on here to read added comments , update to the job of waterpump replacement is that ive had no issues with the waterpump at all & i check it visually reasonably regular ,
I’ll soon be dropping out the coolant & refresh the system with new coolant , while at it ill be replacing the hose seals , i use the G12 Evo & done away with the silica bag & replaced the coolant tank aswell so it means the coolant would more than likely need to be replaced more often .