Gutted - Coolant bypass valve fault

[amacken]

Absolutely gutted, my wife and I have been planning a trip to Lewis and Harris for the last year, due to travel tomorrow. Unfortunately, last week my Ocean was showing an intermittent dash fault which, after diagnosis by AA VW techie, turned out to be a coolant bypass valve fault (P26B100) (apparently it first registered in Aug 2023 but has never shown up on the dash until last week). Called the garage straight away who were really good (Crowsons in Spalding) and they managed to get it booked in for repair this morning. Arrived promptly and the parts company had failed to deliver the part. Unbelievable! Holiday gone, hundreds of pounds wasted

 

[andyinluton]

Absolutely gutted, my wife and I have been planning a trip to Lewis and Harris for the last year, due to travel tomorrow. Unfortunately, last week my Ocean was showing an intermittent dash fault which, after diagnosis by AA VW techie, turned out to be a coolant bypass valve fault (P26B100) (apparently it first registered in Aug 2023 but has never shown up on the dash until last week). Called the garage straight away who were really good (Crowsons in Spalding) and they managed to get it booked in for repair this morning. Arrived promptly and the parts company had failed to deliver the part. Unbelievable! Holiday gone, hundreds of pounds wasted

Sorry to hear.
If the vans under warranty have you tried VW assist providing a hire van?
I have read of others actually having vw assist change it on the drive for them.
Is it a red or orange warning light. If orange just carry on driving.

I have previously found VW assist pretty helpful at times in this sort of situation, nothing to loose by giving them a ring & seeing if they can do anything.

 

[amacken]

Sorry to hear.
If the vans under warranty have you tried VW assist providing a hire van?
I have read of others actually having vw assist change it on the drive for them.
Is it a red or orange warning light. If orange just carry on driving.

I have previously found VW assist pretty helpful at times in this sort of situation, nothing to loose by giving them a ring & seeing if they can do anything.

Thanks Andy, I’ll give VW Assist a ring. It was VW Assist that called out AA (VW technician) to diagnose the fault and he said he wasn’t happy to carry out repair on the driveway, insisted it be driven to garage.

 

[B J G]

When I called out VW Assist they sent AA man who said that they (AA) weren't permitted to fit warranty parts but would fit if I paid for the part. job was reassigned back to VW Assist but it took a week to get the job done.

 

[CaliforniaPhil]

I have just finished doing mine this evening. Just out of the 3 year warranty, 10000 miles. Its not straight forward, fiddly but doable if you have the tools and practical knowledge, I'm a competent diy mechanic. I have a low rise lift, so I can get the van about 1ft of the floor (under the wheels) before it hits the ceiling. About the same as some good ramps. There might be an easier way of doing it but this is what i did. I read about the vacuum thing but though I could put some corks into the hoses. This didn't work out too good, I kept knocking them out and got covered with coolant. Probably best to just let the bid drain out when you take the pipes off. I lost about 1.5 litres. I used several different sizes of mole grips to compress the hose clips, they don't seem to move down the pipes, so just compressed and prized off. There are pipes connected to fixed metal pipes, I removed the screw holding this and managed to pull it out of the pipe connected to the valve. The valve sits in a metal carrier, you have to take the 2 nuts off to release it, I couldn't get the valve out without doing this. I left a short pipe on the valve. You will need several different length torx 30 and 10mm socket. Its tight, not much room. Its hard to compress the hose clips and get the pipes off. Don't forget the electrical connection, press in the cilp in the indentation and ease off with a screwdriver. When you get the new one in, remember which pipes you need to leave off to put the screws back in. The top 2 screws in the valve were hard to line up. Filled back up with some new coolant, ignition on and the little pump next to the valve circulated the water. The dash shows bleeding coolant. This takes about 5 minutes, check level again. Clear the error code, check for leaks and put the bash plate back on. £250 for the valve £45 for some more antifreeze. (Could have just got 1 litre). I did buy VCDS to diagnose it, I was looking at it before the fault as we have 3 VW's in the family. I think VW are charging around £700, I didn't get a quote, an intent search suggested this.

 

[Zeppelin2]

I have just finished doing mine this evening. Just out of the 3 year warranty, 10000 miles. Its not straight forward, fiddly but doable if you have the tools and practical knowledge, I'm a competent diy mechanic. I have a low rise lift, so I can get the van about 1ft of the floor (under the wheels) before it hits the ceiling. About the same as some good ramps. There might be an easier way of doing it but this is what i did. I read about the vacuum thing but though I could put some corks into the hoses. This didn't work out too good, I kept knocking them out and got covered with coolant. Probably best to just let the bid drain out when you take the pipes off. I lost about 1.5 litres. I used several different sizes of mole grips to compress the hose clips, they don't seem to move down the pipes, so just compressed and prized off. There are pipes connected to fixed metal pipes, I removed the screw holding this and managed to pull it out of the pipe connected to the valve. The valve sits in a metal carrier, you have to take the 2 nuts off to release it, I couldn't get the valve out without doing this. I left a short pipe on the valve. You will need several different length torx 30 and 10mm socket. Its tight, not much room. Its hard to compress the hose clips and get the pipes off. Don't forget the electrical connection, press in the cilp in the indentation and ease off with a screwdriver. When you get the new one in, remember which pipes you need to leave off to put the screws back in. The top 2 screws in the valve were hard to line up. Filled back up with some new coolant, ignition on and the little pump next to the valve circulated the water. The dash shows bleeding coolant. This takes about 5 minutes, check level again. Clear the error code, check for leaks and put the bash plate back on. £250 for the valve £45 for some more antifreeze. (Could have just got 1 litre). I did buy VCDS to diagnose it, I was looking at it before the fault as we have 3 VW's in the family. I think VW are charging around £700, I didn't get a quote, an intent search suggested this.

View attachment 145676

Hi, great description, do you mind sharing the part number of the valve. I think I have the same issue. Ive attached (or at least tried to) a screenshot of the fault codes Ive got.
Cheers

 

[CaliforniaPhil]

Hi, great description, do you mind sharing the part number of the valve. I think I have the same issue. Ive attached (or at least tried to) a screenshot of the fault codes Ive got.
Cheers

View attachment 148326

Looks like the same fault. My van had the check engine light and the EPC light coming on intermittently.
I think the part number I fitted was 03N906249K. The one on the van ended in H but just looking online there is now one ending in L. Googling it it suggests the last letter is alphabetic, so the latest part is the L one. You will have to check at VW. You will also get a vacant stare when you ask for a Bypass Valve. Their parts system call it a Control Unit for the Coolant Curcuit.

 

[Zeppelin2]

I have just finished doing mine this evening. Just out of the 3 year warranty, 10000 miles. Its not straight forward, fiddly but doable if you have the tools and practical knowledge, I'm a competent diy mechanic. I have a low rise lift, so I can get the van about 1ft of the floor (under the wheels) before it hits the ceiling. About the same as some good ramps. There might be an easier way of doing it but this is what i did. I read about the vacuum thing but though I could put some corks into the hoses. This didn't work out too good, I kept knocking them out and got covered with coolant. Probably best to just let the bid drain out when you take the pipes off. I lost about 1.5 litres. I used several different sizes of mole grips to compress the hose clips, they don't seem to move down the pipes, so just compressed and prized off. There are pipes connected to fixed metal pipes, I removed the screw holding this and managed to pull it out of the pipe connected to the valve. The valve sits in a metal carrier, you have to take the 2 nuts off to release it, I couldn't get the valve out without doing this. I left a short pipe on the valve. You will need several different length torx 30 and 10mm socket. Its tight, not much room. Its hard to compress the hose clips and get the pipes off. Don't forget the electrical connection, press in the cilp in the indentation and ease off with a screwdriver. When you get the new one in, remember which pipes you need to leave off to put the screws back in. The top 2 screws in the valve were hard to line up. Filled back up with some new coolant, ignition on and the little pump next to the valve circulated the water. The dash shows bleeding coolant. This takes about 5 minutes, check level again. Clear the error code, check for leaks and put the bash plate back on. £250 for the valve £45 for some more antifreeze. (Could have just got 1 litre). I did buy VCDS to diagnose it, I was looking at it before the fault as we have 3 VW's in the family. I think VW are charging around £700, I didn't get a quote, an intent search suggested this.

View attachment 145676

Hi, great description, do you mind sharing the part number of the valve. I think I have the same issue. Ive attached (or at least tried to) a screenshot of the fault codes Ive got.
Cheers

Looks like the same fault. My van had the check engine light and the EPC light coming on intermittently.
I think the part number I fitted was 03N906249K. The one on the van ended in H but just looking online there is now one ending in L. Googling it it suggests the last letter is alphabetic, so the latest part is the L one. You will have to check at VW. You will also get a vacant stare when you ask for a Bypass Valve. Their parts system call it a Control Unit

Looks like the same fault. My van had the check engine light and the EPC light coming on intermittently.
I think the part number I fitted was 03N906249K. The one on the van ended in H but just looking online there is now one ending in L. Googling it it suggests the last letter is alphabetic, so the latest part is the L one. You will have to check at VW. You will also get a vacant stare when you ask for a Bypass Valve. Their parts system call it a Control Unit for the Coolant Curcuit.

Brilliant, thanks for getting back to me. I found what I thought might be the correct part on VW Van parts and they call it a heat exchanger control valve but the part number matches what you have so thanks for that. I'll get one ordered and crack on with it.
Cheers

 

[Zeppelin2]

Well I finally got round to replacing this valve and to my relief it has cured the problem. As stated earlier in the thread it is pretty straight forward to do. I did it on my drive with the front of the van up on chocks. The most challenging part is probably the hose clips, they're always fun, and also avoiding a face full of coolant! You don't loose much coolant, I caught nearly all of it in a clean bucket and once I was finished I filtered it and poured it back in. I really like the self bleeding feature, very handy.
I dread to think what VW will charge if you just took it to them.
I opened the old valve up for a look and it is pretty clear it has leaked internally, the electrical side is soaked with coolant which explains the P2683 fault but also the valve itself was really stiff to turn manually which also explains the P26AB fault.
A bit disappointing really, the whole valve assembly is plastic and clearly prone to failing.
I wonder how long the replacement will last??

 

[CaliforniaPhil]

Well I finally got round to replacing this valve and to my relief it has cured the problem. As stated earlier in the thread it is pretty straight forward to do. I did it on my drive with the front of the van up on chocks. The most challenging part is probably the hose clips, they're always fun, and also avoiding a face full of coolant! You don't loose much coolant, I caught nearly all of it in a clean bucket and once I was finished I filtered it and poured it back in. I really like the self bleeding feature, very handy.
I dread to think what VW will charge if you just took it to them.
I opened the old valve up for a look and it is pretty clear it has leaked internally, the electrical side is soaked with coolant which explains the P2683 fault but also the valve itself was really stiff to turn manually which also explains the P26AB fault.
A bit disappointing really, the whole valve assembly is plastic and clearly prone to failing.
I wonder how long the replacement will last??

View attachment 148653

It was the same with mine, not sure how wet it was inside but it was very stiff to turn. Which part number did you fit in the end, H, K or L?

 

[Zeppelin2]

It was a K. Im not sure what the knackered one was and can't check right now

 

[sidepod]

Almost as if VW have cut costs to the bone favouring profit over longevity

 

[Zeppelin2]

Never!