98 V70 Hepu WP Gasket & Freeze Plug Leaking Topic is solved

Post by **sleddriver** » 22 Mar 2016, 14:11

Finally got around to jacking up the pass side, removing the wheel, and having a good, close look. Saw evidence of the WP freeze plug leaking and also noticed some water around the bottom of the gasket. No evidence of coolant through the weep hole.

This area was a mess due to a previously fixed new outer CVJ-boot. Slung grease everywhere. Turns out the pass-side Conti/Rein outer boot I installed last year has already split! How pathetic! No more "Rein-Rubber" for me. Sprayed it all down with Greased Lightning degreaser, let it soak 10min., brushed it to loosen the crud, then hosed off with a pump-up sprayer filled with a gallon of 140°F water. Did a good job.

The Sled needs all new coolant hoses. I'm also going to pull both the timing & serp. belts, so I can spin the pulleys and listen for rough bearings. These were all replaced last TB. I also want to pull the WP and inspect it. Odd that it has a freeze plug. Then again, it is at the low point.

Meant to take a photo, but it was just way too dirty before. May snap some if time permits.

Post by **benpineapple** » 22 Mar 2016, 14:40

Yeah, pics would be great. I just installed a Hepu water pump last weekend when doing the timing belt job. You're making me nervous.

How many miles on the water pump?

Post by **precopster** » 22 Mar 2016, 15:26

Reports of the Hepus not being up to scratch have been filtering in now for 2-3 years on this forum. I have one on my XC70 motor that just went into the V70 T5. It hasn't done more than 300kms so time will tell...

Post by **erikv11** » 22 Mar 2016, 19:20

Sorry to hear, looks like Aisin is still the only sure way to go on the water pump. GKN/Lobro on the axle boots if you can still find them.

So many of these OEM water pumps replaced when they didn't need to be ... just so a mechanic or parts guy could make a buck! My advice to the next readers: leave 'em in at least until the third timing belt / 210k or so. They will weep or get noisy when the time comes; still many P80 cars are not beyond that interval.

Post by **cn90** » 22 Mar 2016, 20:34

CV Boot: GKN Lobro only. For INNER boot, search forum for "Audi boot".

WP: Aisin is OEM. HEPU is good too, many people use HEPU w/o issues at all.
However, Aisin is the way to go.

Post by **rguzz** » 23 Mar 2016, 13:15

1996 Audi A6 Hepu has been in place less than 18 mos and leaks from freeze plug! I am more than annoyed. Also as I posted the Wahler T stat leaves me with a gauge that is all over the map, presumably from a weakened spring or other part. So, OEM for both from now on for me.

Post by **precopster** » 23 Mar 2016, 15:18

Did you replace ECT? Wahler is a reboxed genuine which can also fail in a rare instance.

Post by **sleddriver** » 23 Mar 2016, 16:39

benpineapple wrote:How many miles on the water pump?

Installed on 8/20/2007. Mileage accrued since then: 71,707 mi.

Was under there yesterday, replacing the two front "rubber mounting plugs" for the IPD skid-plate. These eventually succumb to rubber-rot, which causes the SP to flap at speed, so I removed it a few years ago. Way things have been going lately, I reasoned I was pressing my luck. I went back with much larger "rubber nuts" from the local hardware store, which just fit the hole when lubed with silicone grease. Still missing one side bolt & plate, so it has 5/6 points of attachment.

I noticed I had a unique angle on the WP while laying under the front pass. side, looking up towards the front pass. wheel. Folded back the plastic splash panel and used a small mirror to reflect some sunlight up into there. Noticed the block was wet where the front engine mount is. Also noticed it was wet on the firewall side of the WP gasket. Unfortunately, I couldn't see the bottom of the WP gasket as the wheel was still installed. There were also a few drops of coolant on the oil thermostat? valve...just to the right towards the front bumper. I also found a very small leak where the upper radiator hose connects to the radiator. It was trickling all the way down to the bottom. About 1 drip/3min. with a cold engine. I'd cleaned + dried out this whole area with an air gun previously + with engine heat the day before, so this is freshly-leaked coolant.

I'm putting together some notes on buying a TB kit, but not sure what actually needs replacing without first verifying. I have the hydraulic tensioner and it's not original. No signs of leaking. Front & rear camshaft seals have been replaced and there's no leaks. Front crank seal was also replaced last time.

I'm catching up on other ignored "do-to's" since the sled has taken over given the ECC issue, then the WG adjustment.

Post by **rguzz** » 23 Mar 2016, 19:48

I should have clarified above comment by saying no problem with 850 cooling (OEM T stat), ECT, have no idea of WP but no leaks so well enough. It's the Audi that was the problem. OEM T stat for that car is Behr, WP will be dealer rebuilt. I'm not sure Wahler makes poor quality stuff, just the Hepu pump now recognized on Audi forum to be suspect in it's quality, clearly has leak at the freeze plug.

Post by **sleddriver** » 25 Mar 2016, 13:38

Update:

Nosing around yesterday under the hood, I suddenly remembered that while replacing the coolant temp sensor, that the gasket on the Wahler T-stat was split. I couldn't remember if I used anything on it or not temporarily. Given the previous find that the front engine mount was "all wet" with coolant running down the block, the t-stat gasket could be at fault. Sure enough, it was split and brittle showing cracks in other places. Fortunately, the local AZ had a replacement.

While examining the bottom of the t-stat cover, I noticed some black crud in there, on the t-stat spring, and around the t-stat lower housing, where it sits when cold. Looks like black rubber from inside a coolant hose, possibly the upper coolant hose due to its proximity. I peeked in there with a light and its very rough and broken down internally. Definitely time for new hoses.

I decided to "lap in" the bottom of the t-stat cover to get it back to shiny aluminum, remove a bit of crud and ensure that it's flat. Cleaned up the ends as well with a brass brush chucked in the drill press. Firmly tightened it down, reinstalled the hoses, started the engine, let it warm up and watched this joint. Once hot, it began leaking from the overflow hose/t-stat cover junction. I used a 1/4" socket to firmly tighten the hose clamp until no more coolant escaped. That's one (forgotten) coolant leak taken care of.

I also removed the serp. belt and found it to be in excellent shape: No cracks what-so-ever. Also spun the two pulleys and heard nothing. No movement either. These three things were replaced in 2011.

I peered down into the TB cavity and see that coolant has returned. It's hanging on a small shelf, on the left side, just below the midpoint of the WP. Meant to take a photo but my Canon Powershot is yet again experiencing the "E18" lens error (Canon's version of P0455....) and refuses to cooperate.

So my order includes: WP, TB, OEM coolant hoses, lower torque mount, front brake pads, rear pads & rotors.