97 Passat coolant leak @ reservior

herbigp

Member
Joined
Jan 27, 2011
Location
Port Ludlow, WA
TDI
1997 Passat, 1998 Jetta
I have a 97 Passat tdi w/ 97k original miles. Timing belt, injection pump, water pump and tensioner belt were replaced by PO's dealer @85k miles. I have since replaced radiator and plastic y fitting. Now reservior is leaking fast. No smoke/steam, plenty of power. I had put almost all distilled water to refill. Today i add pink G12 coolant and water in top section of reservior is circulating but G12 cooland is sitting in bottom of reservior not mixing.

I just ordered a thermostat and reservior w/cap and am going to try that, then possibly water pump? I saw no other leaks in the engine bay or around the water pump.

Any insights or suggestions?
 

TonyJetta

Top Post Dawg
Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
The reservoir itself can be had for <$25, so it may be just as well to replace it and remove any questions about it.

If the coolant isn't circulation, I wonder if your pump is intact, or if there is a blockage in the coolant system.

Usually, you can see a small stream of liquid filling the bottle from the small hose that connect to the three-way flange.

Tony
 

herbigp

Member
Joined
Jan 27, 2011
Location
Port Ludlow, WA
TDI
1997 Passat, 1998 Jetta
I agree Tony, the reservior bulb and cap is on the way.

There is coolant entering from the smaller side tubes. So the coolant must be flowing out. I just did not see the pink G12 mixing with the mostly H2O coolant after adding G12?

I will update when bulb and cap are replaced.

Thanks
 

herbigp

Member
Joined
Jan 27, 2011
Location
Port Ludlow, WA
TDI
1997 Passat, 1998 Jetta
I installed the new coolant bulb and cap and it is holding coolant well.

Only taken on short drives. I have concern over the fluctuating coolant temps using VagCom.

Running temps varied from 72.9C to 76.5C and then after driving the idle temps varied from 71.1 to 72.9. The idiot gauge was going between 175F and 195F.

My Jetta rarely fluctuates at all.

Any comments?

Thanks
 

Yblocker

Veteran Member
Joined
Sep 1, 2010
Location
Oakland, CA
TDI
1997 Passat
Have you installed the thermostat you ordered? Sounds like the one in there now isn't working right, or the sender is off. I replaced the thermostat in my '97 recently, and found that to avoid doing the job twice (like I did), the plastic housing, o-ring and lower hose adapter should be changed along with the thermostat. Don't forget the o-ring between the housing and the block.
 

TonyJetta

Top Post Dawg
Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
For the older cars, you can look up VW PN's on vagcat.com Free to register.

Tony
 

Yblocker

Veteran Member
Joined
Sep 1, 2010
Location
Oakland, CA
TDI
1997 Passat
As far a tips on the procedure, obtain the parts first. Get the car on stands so you can get underneath. You'll have to undo the spring clamp on the lower hose to drain the coolant, and a pair of spring clamp pliers really makes it easy, but channel locks can be used instead. Using the nicest pot in the kitchen that is used for spaghetti prep, try to catch as much coolant as you can after you pull the hose of the adapter. Clean up the spillage. Hint: Don't tell your wife that you are storing coolant in household cookware.

You need to drop the power steering pump and bracket to get at the t-stat housing bolts. There is a bolt on the back side of the pump that retains adjustment, and a bolt and adjustment wheel on the front side that need to be removed. Then the large 16 mm pivot bolt needs to come out, and it may need some persuasion, but it will come. Then the pump can drop down out of the way, allowing you to remove the three vertical bolts that retain the pump bracket to the block.

Now you can easily remove the two 10 mm bolts that hold the housing. Be ready for more coolant spill.

If you have the new housing and adapter and o-ring, assemble them and retain with the spring clip from the old set. I do recommend as a minimum that you at least replace the o-ring that fits over the shank of the t-stat housing that the adapter fits over. Lube it with some coolant or better yet some silicone grease.

Holding the t-stat in the block while you position the o-ring and housing assembly can be done by applying vacuum with a shop vac or vacuum cleaner to the coolant reservoir. The vacuum will hold it up there so you can get the o-ring and housing on squarely. Snug up the bolts, then reassemble the other stuff.

If the coolant looks nice and pink you can re-use it. You may have to strain the bits out that may have fallen in the pot along the way. It's likely that you'll need some extra G-12 to top off, since spillage is virtually unavoidable.

Drive the car on a short trip close to home, and expect to have to top off the reservoir since you'll have air in the system that will burp.

Don't forget to clean that spaghetti pot!
 

herbigp

Member
Joined
Jan 27, 2011
Location
Port Ludlow, WA
TDI
1997 Passat, 1998 Jetta
Coolant Leak

OK, first I just wanted to say thanks for everyones input.

I did replace the thermostat & gasket ring.

Now I am maintaining a steady coolant temp at 195F.

I still get the low coolant light after about 50 miles. I let the car sit and cool and the coolant level rises back up but not all the way up.

I saw no evidence of pink G12 out of the thermostat flange, waterpump, any hoses. Only from the coolant reservior overflow. I had replaced the reservior just before the thermostat.

I seem to have good power and only a little white smoke at startup, not much.

Any testing I can do to determine the headgasket is the problem?
 

TonyJetta

Top Post Dawg
Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
You replaced the reservoir...did you also replace the reservoir cap?

Tony
 

Abacus

That helpful B4 guy
Joined
Nov 10, 2007
Location
Relocated from Maine to Dewey, AZ
TDI
Only the B4V left
Did you run the system up/down the road with the reservoir cap off or ajar to let any trapped air escape?

Some people had good luck with the Block Tester, but it showed nothing in my case.

I had the same symptoms, but when I released the pressure on the cooling system, air would come out. I had a very slight buildup of soot in the reservoir, like barely any after months, with no sign of oil in the coolant and no coolant in the oil as per an oil analysis (on the oil).

You might grab a sample of coolant and have it tested.

I'd try purging the air first, which can take a little while after it comes up to temp. If that still doesn't work, definitely check back in.
 

herbigp

Member
Joined
Jan 27, 2011
Location
Port Ludlow, WA
TDI
1997 Passat, 1998 Jetta
Coolant Leak

I did replace the reservior and cap.

Before starting my car today first thing in the AM I unscrewed the cap to the reservior and the coolant system was pressurized as if the engine was hot? This is different!

I did top it off and drive around the block with the cap off then burped the hoses.

I drove all day with out the coolant light coming on, but it was low?

Any thoughts?

Thanks
 

Yblocker

Veteran Member
Joined
Sep 1, 2010
Location
Oakland, CA
TDI
1997 Passat
Hmm. My car uses no coolant and it maintains pressure like that. I think these cars do that. Your drop in coolant over 60 miles is significant though, and if you can confirm no external leaking, and if the system is fully bled, then it has to be burning it either via a head gasket leak or a crack in the head.
 

herbigp

Member
Joined
Jan 27, 2011
Location
Port Ludlow, WA
TDI
1997 Passat, 1998 Jetta
Coolant leak

I see where the coolant is coming out of the reservior, not the cap, but the side vent. I am still seeing evidence of coolant down below the reservior. But I replaced the reservior and cap?

I do not want to pull the head, but that seems to be the answer at this point?
 

Abacus

That helpful B4 guy
Joined
Nov 10, 2007
Location
Relocated from Maine to Dewey, AZ
TDI
Only the B4V left
Sounds like you are building too much pressure, like Yblocker said. I am assuming you are seeing no black buildup in the coolant reservoir and no other indications of coolant or other migration?

It may also be from the EGR cooler, so you can bypass that and take it out of the loop. No need to get additional hoses, the ones for the heater core will work just fine. But, I'm thinking head gasket as well, since that is exactly what mine did for quite awhile.

I found that if I released the pressure slowly from the reservoir as soon as I shut it down, I could minimze the coolant loss.

Do this: after running it around at the end of the day, turn it off. Slowly release the pressure via the reservoir cap, trying not to lose coolant (wiggle the cap back and forth to get it to slowly release otherwise it can go all at once). YOu won't get burned since it'll just purge out the overflow, like you are seeing now (on the side). Then put the cap back on tight. In the morning, remove the cap again before you start it and if pressure has built back up overnight, then odds are very good it's your head gasket. Mine did this.

Some people have had good luck swapping to the ARP2000 head studs to 'cure' the head gasket leak, but it did nothing for me.
 

herbigp

Member
Joined
Jan 27, 2011
Location
Port Ludlow, WA
TDI
1997 Passat, 1998 Jetta
Thanks.

I removed the EGR recently, so I think that can be ruled out. I have done what you described as far as bleeding the reservior. I will do that a few more times?
 

herbigp

Member
Joined
Jan 27, 2011
Location
Port Ludlow, WA
TDI
1997 Passat, 1998 Jetta
Pretty sure it is Head Gasket. After examining old coolant bulb, I see lots of black above max fill line. I also just noticed black (probbbly oil) on the inside of new bulb.

Any suggestions on other things to do when changing head gasket? Timing belt, water pump, tensioner was replaced 4k ago and the injection pump was replace 8k ago. All this work was perfomed by PO at dealer.

I need to get my AC blowing cold, wondering if I should trouble shoot now or wait till HG replacement? Am also thinking of having head cleaned & rebuilt?

Any input would be great.

Thanks
 

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
First, I can count the number of reservoir caps that needed to be replaced on one finger... it got lost by the owner.

Second, the level of your coolant should RISE when hot and FALL when cool; not the other way around. Something is very wrong there.

If you remove the reservoir lid and there is venting, you are pressurizing your coolant system from a blown head gasket. That is all...

If you are losing that much coolant, it should make itself apparent. If you are using the G-12 antifreeze, it will leave a tell-tale trail of pink foamy stuff or at very least a pink trail from the offending part, that is, unless it's going out the tail pipe.

If the coolant is disappearing 'without a trace', (which it never really does), then check tail pipe for steam, smell of antifreeze. If that's where it's coming from, then either you have a head gasket leak or you have a holed EGR cooler.

The EGR is easy to trouble shoot. Take it off and pull a vacuum on the water leads. If it's your head gasket, the most common leak is between the #2 and #3 pistons and the two center pistons will read low compression compared to the other two cylinders. The two center cylinders will compare in readings quite closely.

In summary, the head gasket will blow when there has been a severe enough loss of coolant to cause the overheat light to blink. Did that ever happen? They should call that light the 'you just blew your head gasket' light.

The warping that follows requires redecking the head gasket surface and usually, an align bore to straighten out the cam shaft. Unfortunately, when the head warps, it is not very likely that you'll get the head bounced back to perfect flat. Since the head warps completely through and the cam journals need to be within about .004", that requires a cam align bore.
 

herbigp

Member
Joined
Jan 27, 2011
Location
Port Ludlow, WA
TDI
1997 Passat, 1998 Jetta
Thanks Frank.

Yes the blinking red light has come on. I stop then fill.

So I pull the head. I read you are the one to send a TDI head to to get it fixed properly (one time)? Can I get a general estimate? Also what do you recomend for shipping procedure? How long does this usually take?
 
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