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Engine Specific Info and Questions => IDI Engine => Topic started by: allsierra123 on October 07, 2009, 04:45:30 am

Title: Waterpump differences?
Post by: allsierra123 on October 07, 2009, 04:45:30 am
Just curious if there is a difference in the AAZ the 1.6td and the 1.6 NA waterpumps? I realize there is a different hub size for the pulley, But is it all interchangeable? I thought the AAZ had more hoses going into it.
Title: Re: Waterpump differences?
Post by: gilligan5000 on October 13, 2009, 01:29:27 pm
the 40 and 30 are different.  I attempted to put a 30 on my block...the v-belt pulley was about 1" off (side to side, not the length of the belt).  Not to mention that the housing is different too, the pump doesn't get close enough to the cone inside to actually move any water.  I also tried to use an early 1.8t passaat waterpump housing because it only has the one output (I deleted heat :) didn't work either...
Title: Re: Waterpump differences?
Post by: Turbinepowered on October 13, 2009, 02:53:11 pm
the 40 and 30 are different.  I attempted to put a 30 on my block...the v-belt pulley was about 1" off (side to side, not the length of the belt).  Not to mention that the housing is different too, the pump doesn't get close enough to the cone inside to actually move any water.  I also tried to use an early 1.8t passaat waterpump housing because it only has the one output (I deleted heat :) didn't work either...

Isn't the 30mm waterpump hub the early and the 40mm the late? I've successfully put an '89 Fox water pump and body on a '79 diesel, just had to hunt up a diesel water pump pulley to affix to it.
Title: Re: Waterpump differences?
Post by: Rabbit on Roids on October 13, 2009, 05:05:26 pm
i have a newer gas (90s) water pump on my 1.5. didnt they quit building 1.5's in 1980? my car used to have the early big hub pump on it, but now the small hub one is on there just fine, and like the previous poster said, i had to get the right pulley for everything to line up right.
Title: Re: Waterpump differences?
Post by: Turbinepowered on October 13, 2009, 07:42:51 pm
i have a newer gas (90s) water pump on my 1.5. didnt they quit building 1.5's in 1980? my car used to have the early big hub pump on it, but now the small hub one is on there just fine, and like the previous poster said, i had to get the right pulley for everything to line up right.

Did they go from large hub to small? I thought it was the other way around.

Either way, it's all a matter of getting the right pulley for your app!
Title: Re: Waterpump differences?
Post by: Rabbit on Roids on October 14, 2009, 09:13:26 am
i have a newer gas (90s) water pump on my 1.5. didnt they quit building 1.5's in 1980? my car used to have the early big hub pump on it, but now the small hub one is on there just fine, and like the previous poster said, i had to get the right pulley for everything to line up right.

Did they go from large hub to small? I thought it was the other way around.

Either way, it's all a matter of getting the right pulley for your app!

yea, big hub was old. small hub was newer style. do they ever revise something and ACTUALLY BUILD IT TOUGHER?!
lol, no, they build it less expensively. haha. but yea, i agree. they have just about every pulley to put just about every different water pump on your engine. i think my pulley is a gasser unit, but its backwards. or maybe that was my other engine? i cant remember 100%
Title: Re: Waterpump differences?
Post by: Turbinepowered on October 14, 2009, 11:48:51 am
yea, big hub was old. small hub was newer style. do they ever revise something and ACTUALLY BUILD IT TOUGHER?!

1.6 diesels going from 11mm head bolts to 12mm headbolts? :D That was a tougher revision than original. :D
Title: Re: Waterpump differences?
Post by: matt-stunt on January 23, 2011, 02:55:51 pm
does anybody know what year they switched from big to small hub?
Title: Re: Waterpump differences?
Post by: Powered by Spearco on January 23, 2011, 08:20:01 pm
I think it was '79 or '80 they went to the small hub.

By the way, the same water pump is on the MK3 Golf/Jetta gas 4cyl.and the B5 Passat 4cyl 1.8t engines,  the same water pump also had a coolant drain bolt plug at the bottom. Kinda nice.
Title: Re: Waterpump differences?
Post by: Quantum TD on January 23, 2011, 09:37:28 pm
I think it was '79 or '80 they went to the small hub.

By the way, the same water pump is on the MK3 Golf/Jetta gas 4cyl.and the B5 Passat 4cyl 1.8t engines,  the same water pump also had a coolant drain bolt plug at the bottom. Kinda nice.


Not exactly. The B5 WP is specific to that model AFAIK. If you look closely at it, it does not work on early 1.5-2.0 cars. It only works on 1.8T motors between 1997-1998. The impeller is different, and the WP housing only has 1 port, instead of 2 (as on earlier cars).

Title: Re: Waterpump differences?
Post by: rabbitman on January 24, 2011, 01:31:05 pm
The 40mm hub ones also have two options for nose length, it's like 2 5/8" and 2 7/8" or something close.
Title: Re: Waterpump differences?
Post by: matt-stunt on January 24, 2011, 08:18:26 pm
thanks for the help. i got the pump i needed. it turns out advanced auto sucks and only listed the 30mm for all years of the 1.6D napa had two options so remember that for next time
Title: Re: Waterpump differences?
Post by: dsl_53b on January 25, 2011, 02:13:44 pm
I think it was '79 or '80 they went to the small hub.

By the way, the same water pump is on the MK3 Golf/Jetta gas 4cyl.and the B5 Passat 4cyl 1.8t engines,  the same water pump also had a coolant drain bolt plug at the bottom. Kinda nice.


Not exactly. The B5 WP is specific to that model AFAIK. If you look closely at it, it does not work on early 1.5-2.0 cars. It only works on 1.8T motors between 1997-1998. The impeller is different, and the WP housing only has 1 port, instead of 2 (as on earlier cars).


FYI- 81 was the change over from 42mm to 30mm flange. Also, the 1.8t waterpump rotates counter clockwise.

Title: Re: Waterpump differences?
Post by: dsl_53b on January 25, 2011, 05:23:54 pm
The ccw pump I am referring to is for 98-00 passat 1.8t and 97-00 a4 1.8t. Part # 026121005f or 026121005l for impeller portion. Housing part I can't recall the pn. Impeller and housing together is 050121010c. I show that the pump for 95-97 1.8t is the same as rabbit 30mm. 026121005c or 037121005c. Looks like the 98-00 housing will bolt right up to our block as the bolt pattern is the same. Still, don't know for sure till you try.
Title: Re: Waterpump differences?
Post by: Powered by Spearco on January 25, 2011, 07:32:52 pm
Listen, the pump housing for a X-flow motor has two outlets, as do the 1.6L diesel or gas 1.7L and 1.8L and the AAZ and AHU. The pump housing on a 1.8t "AEB" eng. code has one outlet. I'm pretty sure the 1.6L gas or diesel, 1.9L AAZ and AHU are the same "pump". They all rotate the same direction... clock wise.

The hub spacing might be different, but is still the smaller 30mm style. The longer spacing is most likly for the serp. belt setup.

Who cares if its different spacing, use a different pully to mach up the correct belt alignment... unless you are doing a direct replacement. Then replace it with the correct pump with the spacing needed.