questions changing water pump on Mk2 with AC and power steering

[92EcoDiesel Jetta]

I just installed a new water pump made by Graf in my Eco. Unlike the old pump, which has a cast iron impeller, the Grap is a totally different design with a stamp sheet metal impeller. I took a long drive today and noticed idling in traffic, the temp gauge sits a little higher than the old pump. That shows the old pump moves more water at idle.

Another problem I am having is a a bad high frequency vibration starting at 2500 rpm and up. It is most noticeable in the throttle pedal, where I can feel it tingling my foot. This vibration was not there before I changed the water pump. Along with the water pump, I also changed the timing belt and tensioner and advanced the timing from 1.00 mm to 1.03 mm. Can advancing the timing be the cause of this vibration? 1.03 mm is within spec per the Bentley for my engine (1V).

I certainly hope it is not the water pump since it is not a fun job and I'd hate to have to do it again. I did torque every bolt to spec. I will go and check my work and see if I can find the source of the vib. Meanwhile, if you have an inputs, I'd like to hear it.

[srgtlord]

The tool you posted looks like the zdmak tool I purchased on ebay a year ago. I did a quick search on the quality of the tools and the reviews were good . Do a search on their page for MK-142BG  http://www.zdmak.com/wbstore/main.asp

[CRSMP5]

yea stamped run hotter... and there is 2 kinds.. big cooler round town.. smaller hotter down road...

cat best.. but becommin unotainium.. plastic fail...

[burn_your_money]

Are all 4 injection pump mounting bolts tight? If you forgot about the back one it will cause vibes like you are describing.

[BoostedOne]

Are all 4 injection pump mounting bolts tight? If you forgot about the back one it will cause vibes like you are describing.

Good point.. That bolt is easy to forget!

[92EcoDiesel Jetta]

I think I tightened all 4 but will ccheck tomorrow.

[92EcoDiesel Jetta]

The bolt and special cone nut is missing. Must have vibrated off and lost on the road. I think I have a spare set somewhere. In the meantime can I use a regular bolt nut + washers?

 Vibrations not good in general. What usually breaks if this was unattended to?

Sent from my MB860 using Xparent BlueTapatalk 2

[92EcoDiesel Jetta]

I put in a regular nut/bolt/ washer for now and the vibration is gone.
 Anyone have a special cone nut if I can't find mine?

Sent from my MB860 using Xparent BlueTapatalk 2

[CRSMP5]

do not ask a dealer how much... if you do sit down first...

[TylerDurden]

Tapered nut: 068130197 ; 068130143

$4.27

http://www.jimellisvwparts.com/products/Volkswagen-VW/1986/Jetta16L-TD5-MT/Tapered-nut/5140968/068130197.html


(You might need the bushing too.)

[92EcoDiesel Jetta]

Tapered nut: 068130197 ; 068130143

$4.27

http://www.jimellisvwparts.com/products/Volkswagen-VW/1986/Jetta16L-TD5-MT/Tapered-nut/5140968/068130197.html


(You might need the bushing too.)

Thanks.

Bushing?  I thought it's just a bolt and the tapered nut? The images on the site don't work for me so I'm not sure what the part looks like.

[92EcoDiesel Jetta]

Are all 4 injection pump mounting bolts tight? If you forgot about the back one it will cause vibes like you are describing.

Another symptom I did not mention in addition to the throttle pedal vibration was a surging while accelerating at speeds around 55 MPH. The surge rate was approx 2 hz and lasts a second or two if I let up on the pedal. I assume it is related to the missing back bolt. What is actually happening in the IP that would make it do that? Is the pump twisting at a 2 hz rate somehow interfering with the fuel being injected?

[TylerDurden]

^ Ja, the harmonics are wicked. They prolly interfere with the swing of the governor weights, causing movement that shifts the control collar.


As for the bushing, it is like the bushing for the alternator bracket, but it has the tapered recess to fit the nut. It is usually trapped by the IP, but check for it being there, just in case...

[92EcoDiesel Jetta]

^ Ja, the harmonics are wicked. They prolly interfere with the swing of the governor weights, causing movement that shifts the control collar.


As for the bushing, it is like the bushing for the alternator bracket, but it has the tapered recess to fit the nut. It is usually trapped by the IP, but check for it being there, just in case...

My bushing is still there. Is 33 the bushing? Pic does not show the split in the (brass) bushing that's in mine.

I got a used tapered nut and bolt installed and torqued down. No more vibration or surging.

[TylerDurden]

Ja #33 is the bushing. I don't think it is supposed to have any split.