Print Page | Close Window

AAZ overheating issues...

Printed From: The Brick-yard
Category: T3 Section
Forum Name: T3 Engine Upgrades
Forum Description: Forum for tuned or alternative engines.
URL: http://www.brick-yard.co.uk/forum/forum_posts.asp?TID=67518
Printed Date: 28 Mar 24 at 09:35
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com


Topic: AAZ overheating issues...
Posted By: Steve o
Subject: AAZ overheating issues...
Date Posted: 14 Aug 11 at 12:22
Bought a van already converted to an AAZ engine, runs ok but the expansion tank is fitted to the right hand side of the engine. Had a garage look at it and they have linked another expansion tank which is located above the engine bay. Apparently because it's gravity fed, has anyone else had any issues in relation to overheating or locating the expansion rank so I can close the engine lid !!!

Never had an engine conversion before so bear with me and my poor explanation ...



Replies:
Posted By: timmythedog
Date Posted: 14 Aug 11 at 15:01
photographic evidence will help.Smile

-------------
Syncro doka td
T4 Multivan Generation, 151
89 Caravelle Exclusive 2.1
Caravelle GL AFN tdi
53 plate T4 Panel.888 special x factor.
88 DG Panel(uncut)
calypso Atlantic pop.


Posted By: H-G
Date Posted: 14 Aug 11 at 16:00
I thought that they were vacuum fed?  My expansion tank is exactly where the it was for the JX and no problems at all.  

I fitted the cooler thermostat, chemical flushed the system and an oil cooler when I did my conversion.  It now runs cooler than the JX did, even on the long climbs.

Worth checking the blue 'dalek' cap on the main water bottle and than the hose for there to the expansion tank is a tight fit.  MAy also be worth checking that the thermostat is opening as it should and also that the whole system has been filled and bled properly. If you only have a half-full rad then it's going to struggle to cool things down at the back.  I would highly recommend an oil cooler - not the cheapest item to buy, but easy to fit and a damn sight cheaper than a replacement engine.




Posted By: rolo
Date Posted: 17 Aug 11 at 06:30
Expansion tank should be behind no. plate at about same height as header tank, once at right level, is fed and diminished by pressure and suction from the main tank and regulated by the cap on the header tank.
Possibly the air filter has been moved to the right air duct by piping across the original site, if not put it where it should be; if so, a smaller, bottom connected, top filled, non pressured expansion can be fitted on n/s of engine bay


-------------
the last one


Posted By: funkyweasel
Date Posted: 18 Jul 13 at 19:46

Apologies for opening up what looks to be an old thread, but I really want to get to the bottom of these cooling AAZ issues.

I have just completed my AAZ conversion using my own tried and trusted 1996 golf donor AAZ.

I know it has been hot of late (26°C+) but I am still getting 108° at 60MPH on the motorway.

If I back off to 50MPH it goes down to 95°C. Idling it will go down even lower (88°C)

 

What I’ve tried:

- Completely flushed system with degreaser rad flush (multiple hot flushings)

- I have installed a brand new EIS (German built) radiator.

-Have installed a 235mm 25 row Mocal oil cooler with 5/8 inch pipe and high flow thermostatic (80°C) take-off sandwich (also Mocal).

-Installed brand new water pump (installed into golf about 2 months before conversion).

-Installed lower opening 82°C thermostat.

 

Other info.

-I am 100% sure I have bled the system well. I have nothing but coolant coming out of rad bleeder  when running hot.

- I am using 10 litres of coolant to 6 litres of water (so that is 62% coolant, the pink variety).

-I am not loosing coolant and I believe my expansion cap (black one from the original CS engine) is working fine.

-I have measured the temperature with two sensors/gauges… one is a digital meter that I confirmed is ok with a kitchen boiling water test.

- I have recently replaced the radiator fan switch and I have heard the rad fan come on once or twice, when I was bleeding the system.

- The oil cooler has made a big difference to the sump temper (as felt by hand) and the oil cooler itself feels nice and very hot so it must have made some improvement, but I can honestly say I did not see much difference in the water temperature.

 I am now thinking that I am not getting the water flow required to achieve what the original golf did so well with its short set of radiator pipes (and two fan units)

 Questions:

-Has anyone attempted using a coolant circulation pump (e.g. V51 or 0392020039  or VW 078965561) to increase the flow to the radiator?

 - Has anyone replaced the 2 stage fan switch with a switch that brings the fan on at a lower temperature(s)?

 - Is 110°C a concern at 60MPH? I suspect if a hill and a trailer load of camping stuff were involved it would continue to rise.

So frustrating. 



Posted By: syncronized
Date Posted: 18 Jul 13 at 23:34
I replaced the blue antifreeze in all my vehicles last year with the new pink variety (50%) & all of them run a good few degrees hotter now. I'm going to change back to the usual blue type in the VW & see if the temp drops back to its old levels. You say you are running 62% antifreeze, maybe that would exacerbate the problem, as I thought 40 to 50% was optimum before the heat transfer properties of the coolant was reduced?


Posted By: Allanw
Date Posted: 21 Jul 13 at 06:23
Coolant isn't as good as cooling as water is - too muchg can slow down the heat transfer. It can also be a bit viscous.

I don't think that would get you up to 108C though!

You could try straight water just to see, but I don't think it'd be that.


-------------
Allan :-)

'84 T3 Kombi, EJ25 DOHC, apprentice Viking...

Duct Tape can't fix stupid, but it can MUFFLE the sound.


Posted By: funkyweasel
Date Posted: 21 Jul 13 at 08:47

Thanks guys for your coolant comments. I may reduce the ratio, but I think I have found my problem:

I put two temp indicator lights on my dash and ran lines to the two output fan feeds from the dual speed thermostatic switch in the radiator, went for a drive and push the van hard on a hot day and found that the temperature was 110°C and the fans hadn't yet turned on.

 

I have just check my radiator switch and I have the 191 959 481C version which has higher temperature ON value then what I need (i.e: 95-84C, 102-91C).

 

I will get the 251-959-481/K version (87-76/93-82C) and that has gotta be better for the whole system.

http://www.status-vw.co.uk/251-959-481-k-dual-thermo-switch-for-vw-T3-and-vw-t4-1984-1993.html" rel="nofollow -  

Finally some progress.

 
 


Posted By: light
Date Posted: 21 Jul 13 at 16:20
Originally posted by funkyweasel funkyweasel wrote:

Thanks guys for your coolant comments. I may reduce the ratio, but I think I have found my problem:

I put two temp indicator lights on my dash and ran lines to the two output fan feeds from the dual speed thermostatic switch in the radiator, went for a drive and push the van hard on a hot day and found that the temperature was 110°C and the fans hadn't yet turned on.

 

I have just check my radiator switch and I have the 191 959 481C version which has higher temperature ON value then what I need (i.e: 95-84C, 102-91C).

 

I will get the 251-959-481/K version (87-76/93-82C) and that has gotta be better for the whole system.

http://www.status-vw.co.uk/251-959-481-k-dual-thermo-switch-for-vw-T3-and-vw-t4-1984-1993.html" rel="nofollow -  

Finally some progress.

 
 
Just a thought
 
What alternator set up have you used ?
 
I have seen a few aaz/1y conversions that have used the 1y/aaz alternator/water pump serpentine belt setup in their t3`s but have routed the belt wrong resulting in the water pump running backwards  ,the cooling system works around town but don't do the job at motorway speeds


Posted By: funkyweasel
Date Posted: 21 Jul 13 at 18:46
My GOD!! Thanks so much for that little gem, you really may have saved next week's camper holiday.
I looks like the muppet who replaced my Golfs water pump has incorrectly routed the alternator belt (before the conversion took place).
I have checked with ElsaWin and it looks like the 1996 AAZ has a CCW rotating water pump. My AAZ is currently rotating in the oposite direction as the crank.
 
I can't see any markings for the direction of rotation on the water pump. Can anyone confirm that ALL AAZ water pumps should rotate the same way (i.e CCW)?
 
Thanks again for your post.
 
 
 


Posted By: funkyweasel
Date Posted: 21 Jul 13 at 19:41

Actually it looks like the crank rotates CW and according to ElsaWin and an RAC friend of mine the belt should go around the bottom of the water pump (confirming that both crank, water pump and alternator should rotate in the same direction).

 

Having said all that, could someone please check their AAZ and tell me if the above is correct?

Thanks.

 


Posted By: H-G
Date Posted: 21 Jul 13 at 19:45
https://www.google.co.uk/search?q=vw+aaz+cambelt+route&client=safari&hl=en&source=lnms&tbm=isch&sa=X&ei=ByzsUcrnLK3X7Aai5YHYDA&ved=0CAkQ_AUoAA&biw=1024&bih=672#biv=i%7C0%3Bd%7CMn4iHK9BM2GNQM%3A


Posted By: funkyweasel
Date Posted: 21 Jul 13 at 20:25

Success! Smile.

Thanks to those who posted ideas. Espeshlly "light" for putting me on the right track. Just swapped the belt direction around the water pump pully and now I am running cool as a cucumber. Really pushed it to 70MH and could only just get it to 96°C.

 

So glad I didn't go down the auxillary pump route to solve this. 

Just to confirm, my ribbed alternator belt goes around the outside of all three pulleys. I have a 1996 AAZ from a Golf CL.

Cheers.


Posted By: evantis121
Date Posted: 08 Jul 14 at 16:17
Hi Funkyweasel, I've also got a hot running AAZ issue. The needle goes to 2/3 at idle and 3/4 if theres a hill involved. I'm just wondering if it could be the water pump. I'm a bit confused by the posts above though. should it rotate CW or CCW ?? Thanks


Posted By: Twffr
Date Posted: 13 Jul 14 at 12:40
Originally posted by evantis121 evantis121 wrote:

Hi Funkyweasel, I've also got a hot running AAZ issue. The needle goes to 2/3 at idle and 3/4 if theres a hill involved. I'm just wondering if it could be the water pump. I'm a bit confused by the posts above though. should it rotate CW or CCW ?? Thanks

In this thread the narrow 'V' belt would run under the water pump pulley and the wide flat+ribbed belt should run over the top the water pump pulley. The latter runs in the opposite direction to the former so they are different internally. The problem arose because the ribbed belt was put on in the same way as a V belt would and drove the pump backwards and so less efficiently.

What type of belt does your AAZ have?


Posted By: danjdelor@gmail.com
Date Posted: 28 May 16 at 19:31
Hi
I'm hoping you can help me.
I have an AAZ from a 90's Passat with what I think is called a serpentine set up - It has a flat belt with a ribbed side and a smooth side. I have all the common problems of the engine generally overheating under little duresse.
My current set up has the belt running round the outside of the water pump pulley. There is a tensioner arm with an extra small pulley to keep the belt tight. I've just had a go at swapping the belt round so that it cuts round the inside of the water pump pulley turning it Counter clockwise, but there doesn't appear to be enough room between the tow bottom pulleys for this to work. Might I still have a pump which needs to go counter-clockwise? It seems wierd that the set-up doesn't seem to allow the belt to work that way. I'm very confused - is there any way to identify the direction of the pup by age etc and avoid having to remove the water pump and look inside to rule this out?

Any help would be most welcome :-)

Dan


Posted By: danstervan
Date Posted: 28 May 16 at 20:15
Can you take a pic of your setup?
From your description it sounds like you have the fixed alternator and spring loaded tensioner system.
There is a pic in this thread which discusses belt routing and waterpump rotation. However the pic shows the adjustable alternator to tension belt system which may differ from what you have.

http://www.brick-yard.co.uk/forum/overheating-in-the-cold_topic48008.html" rel="nofollow - http://www.brick-yard.co.uk/forum/overheating-in-the-cold_topic48008.html

I found another thread which has different pics which may be similar to your setup.

http://www.brick-yard.co.uk/forum/aaz-crank-problems-a-solution_topic69766.html


Posted By: danjdelor@gmail.com
Date Posted: 09 Jun 16 at 22:31
Hi,
Thanks for the links. I'm fairly new to posting here - not sure if I have permission to upload pics - it just asks for links - do I need to up it to a seperate pic host first? Sorry for the ignorance.
I have a fairly good pic which should show my set up if I can get it on here......


Posted By: danjdelor@gmail.com
Date Posted: 09 Jun 16 at 23:19
Here you go


- I can see from reading the threads  that I'm going to need a clutched alt pulley and must check my crank bolt too. Baxter also suggests that running the serpentine set up with the belt on the inside creates wear on the crank pulley/bolt and that the jx V pulley system is much better - hmm.....
Also my pulley set up seems to look quite different to others in that there doesn't seem to be enough room to put my belt round the inside of the water pump pulley as it sits so close to the crank pulley.
The guy who sold me the engine bought a new pump for it from Brickwerks but they no longer have a record of the sale so I can only hope it's a clockwise one without taking the thing apart. Have you ever had the front off the water pump? Wondering if I can do that as I've read that changing the whole thing can be arduous........
sorry for all the questions - just trying to avoid another engine loss.....





Print Page | Close Window

Forum Software by Web Wiz Forums® version 12.06 - https://www.webwizforums.com
Copyright ©2001-2023 Web Wiz Ltd. - https://www.webwiz.net