VW Golf mk4 TDI ALH thermostat removal and install

[@gregcrabb3497]

Finally someone who shows the tabs inside to hold the new stat in place! Not near as much working room in a Beetle!

[@Corysdiyauto]

Glad you enjoyed the video.

[@vampir335]

Did you drain some coolant from the radiator before doing this? I see in other videos they drain the radiator underneath and then start working, some drain coolant from EGR cooler and oil cooler.

[@Corysdiyauto]

No, I didn't drain any coolant. You can drain some first if you want. It wouldn't be as messy.

[@youtubeleavemealone]

Great video. Thank you for posting. I just have 1 question. After doing this, did you need to bleed air out of the coolant system? Or did it just take care of itself?

[@Corysdiyauto]

Thank you. There's no need to bleed air out. It takes care of itself. Just watch your coolant level in your reservoir afterwards. You'll definitely need to add some.

[@samirsbai9932]

Thank you for your tutorial I have a SEAT Córdoba 1.9 TDI ALH with 90 HP (same engine as your Volkswagen). I have to buy the thermostat flange and tools to change it. That surely weekend I will change it. For curiosity SEAT is a spanish brand form Volkswagen grup as sold in Europe and another countries. That is my car: en.m.wikipedia.org/wiki/File:Seat_Cordoba_front_20081125.jpg Thanks for the tutorial!!

[@Corysdiyauto]

You're welcome and thanks for sharing. We don't have any SEAT Córdoba's here in the USA. I didn't even know what one looked like until now, haha. Thanks for sending the link because I would've looked it up anyways.

[@samirsbai9932]

@@Corysdiyauto Yes, the SEAT brand does not exist nor is it marketed in the USA, but it is in Mexico and other countries. Not only does SEAT belong to VW, but also Skoda, which is a Czech brand of the Volkswagen group that is not marketed in the USA either. Well, the Córdoba is a very good car with a very reliable engine, it only has 233,000 km (145,000 miles). It is my contribution that more than one will arrive, because not only the Golf Mk4, but other brands with the same ALH engine (Audi A3, my Seat, VW Jetta...). Thanks and greeting from Spain 👋👋

[@vampir335]

how many litres of coolant did you refill after the job? cause I saw a big spill there.

[@Corysdiyauto]

It's been awhile since I did this, so I actually don't remember. It wasn't that much though.

[@Rgh71fish]

Great video. How long should an ALH take to get to temperature? From what I've read, an old Tstat can open prematurely, leading to very long warm up times. Im wondering if this may be the case with mine, as I am driving for a good 15 minutes before the needle starts to move. Is this normal?

[@Corysdiyauto]

Thank you. Well, before I replaced mine, it took forever to warm up and it was worse when it was colder outside. My thermostat might have been stuck open because sometimes the gauge wouldn't even get to operating temperature in the winter months. I would say my gauge points at about 190°F after about 15 minutes of driving. It might vary a little bit depending on what the temperature is outside. I should've replaced the thermostat sooner. What a big difference it made!

[@richhunter515]

@@Corysdiyauto how does an EGR delete effect it all? Drove home today in 20°F weather and it never got to operating temp. Thermostat problem or EGR delete is causing it? Thanks

[@Corysdiyauto]

@@richhunter515 - I still have my EGR functional, so I can't comment about that. I know that I could never get to operating temperature when it was cold out with the faulty thermostat. Did you recently delete the EGR?

[@richhunter515]

@@Corysdiyauto I got the car this fall with the EGR already deleted. Knew it made things tougher to warm up but dang this is a whole different level. Blocked off the rest of the grill tonight. We’ll see if that helps.

[@Corysdiyauto]

@@richhunter515 - I would change the thermostat anyways. You don't know if or when it was ever done. It's not that expensive which is nice.

[@andyliv78]

Thanks for the video. Can you confirm only one seal was used eventually, there isnt one 'behind' the stat as it goes into the block? Many thanks

[@Corysdiyauto]

Andrew Maudsley - Yes, just one seal is needed. Thanks for watching.

[@andyliv78]

@@Corysdiyauto thanks. It was a pretty easy job. Did the sender too.

[@Corysdiyauto]

@@andyliv78 - Good job! I'm glad that it worked out for you.

[@adolg4049]

My golf same like your Gauge stays always normal at middle But No radiator and ac working and engine overheats but No Light shown in dashboard so what can be

[@Corysdiyauto]

Your engine overheats with the gauge in the middle?

[@adolg4049]

@@Corysdiyauto yes

[@Corysdiyauto]

Well, there's either something wrong with your temperature gauge or the sending unit is bad. How do you know that you're overheating? Do you see steam?

[@user-hg2zg5qm5r]

Спасибо. Не могу разобраться с температурами. Слабо греет печка, но это вопрос второй. На стрелке ровно 90, Вася диагност показывает на контроллере панели приборов 80, на эбу двигателя 76. Термостат открывается по признакам тепла нижнего патрубка после 70-80 как минимум. Вентилятор включался сам при прогретом двигателе и отключался. Шкода 1.9 тди. Рабочий ли термостат и почему такие разницы температур? Исправен ли четырехконтактный датчик темп?

[@Corysdiyauto]

You're welcome. Your thermostat seems to be working correctly. I think that it's normal to have slight temperature differences like you have. The four-pin temperature sensor seems to be working as well. You can always replace the sensor since it's inexpensive to see if that changes your readings with the Vasya Diagnostician. Just my thoughts on the matter.

[@user-iy1wl4by7k]

Hi. What problem you have? Ti change the termostat?

[@Corysdiyauto]

The coolant temperature wasn't increasing as it should. I could especially tell in the colder weather.

[@vampir335]

you dont need to flush the entire coolant for this fix right?

[@Corysdiyauto]

No you don't.

[@igorandreev2444]

I have a problem with temperature and Don. T work fans... Lower hose I cold... Could be a problem with thermostat?

[@Corysdiyauto]

Does your temperature gauge rise? It's not a good sign that your lower hose is cold. The thermostat might not be opening.

[@supratech20]

you had 2 o rings and only use one??? is thats how it goes on or ?==

[@Corysdiyauto]

Adrian C - Yes, I did have 2 o-rings. They gave me one with the thermostat and one with the housing. You only need one o-ring for the installation.

[@theoldleafybeard]

Thank you, very very clear!! Ah, are the bolts T30 size?

[@Corysdiyauto]

Markel - The bolts are 10mm hex.

[@theoldleafybeard]

@@Corysdiyauto Thank you, I hope it's the same for an AHF motor. :)

[@Corysdiyauto]

@@theoldleafybeard - I'm not familiar with that motor, but I hope so. Thanks for watching and I hope that the video helps you!

[@vampir335]

@@theoldleafybeard ALH is AHF, one for USA the other for other countries south africa mexico etc but they are identical

[@peterdaniel66]

do you worry about air pockets and if so, how to do prevent that or at least get rid of them?

[@Corysdiyauto]

I don't worry about them, no. If you have air trapped in your system, it's fairly simple to get out. There's a lot of write ups on the matter and there's a few videos out there as well. Do you have air trapped in your system?

[@arminderkhaira2994]

Thank you for the video very helpful, when I did mine the coolant didn't pour out when I removed the stat like in your video, so does this suggest I have another issue? Issue is overheating but no leaks anywhere and my in car heating is not working. Thank you

[@Corysdiyauto]

Be sure to check your coolant level in the reservoir.

[@arminderkhaira2994]

@@Corysdiyauto seems to be steady, not dropping. Thinking it could be the waterpump.

[@Corysdiyauto]

@@arminderkhaira2994 - That's a good possibility.

[@BozAwesome]

Is there a top and bottom?

[@Corysdiyauto]

What exactly do you mean?

[@BozAwesome]

@@Corysdiyauto sometimes a thermostats has a hole on the top or bottom to let some fluid continue to flow when shut. Just wondering is there is a wrong way to install it. At the time i heard about people installing them backwards, so i just wanted to see if theres a specific orientation to intall

[@Corysdiyauto]

@@BozAwesome - The thermostat will only go in one way because of the black plastic housing that it goes into. As long as you install the thermostat the way that I did, you'll be fine.

[@zaratrusta79]

how did you not remove the coolant before doing this job??

[@zaratrusta79]

also from the tools you're using I'm curious how you torqued those to specifically 15Nm as you advise... just trying to add some things that could have been improved in this video, otherwise thank you for sharing.

[@Corysdiyauto]

zaratrusta79 - I just didn't. I needed to replace the thermostat and that was it.

[@Corysdiyauto]

zaratrusta79 - I didn't torque them specifically to the exact torque specs. I just stated the correct torque specs for the viewers. I never get crazy with torquing every single bolt/screw to the exact torque spec unless it's something critical such as head bolts or suspension components.

[@Corysdiyauto]

zaratrusta79 - Yes, I did lose coolant, so I just added some after the job was completed. A coolant flush would've been great to do, yes, but all I had time to do was replace this thermostat. It is a quick way to replace a thermostat if you have to get back on the road. At the end of the day, I got the job done and it works! I appreciate your comments though.

[@Corysdiyauto]

@@zaratrusta79 - Good thought! If I were you, I would use a torque wrench on those bolts then. I don't have a torque wrench small enough.