Astra J 1.7 Diesel EcoFlex major coolant loss
Discussion
Evening,
Long post, but hoping someone can help me.
Got a strange issue with my mark 6 Astra J (1.7 EcoFlex diesel, 12 plate 80K miles) - it is using huge amounts of coolant but no sign of a leak.
The coolant leak has got worse over time, until now it gets through about a litre of coolant in 30 miles. The symptoms are that when reaching the end of a journey the coolant level in the tank would look ok, or appear to have dropped slightly. It was only when you restarted the engine after it has cooled down or remove the header tank lid that the coolant level would drop suddenly and majorly. Temperature was rock solid as normal at 90°C on the gauge.
No evidence of an external leak, oil looks ok (no mayonnaise), no evidence of water out of the exhaust, coolant in the header tank looks ok (no oil evident).
Took it to my local Vauxhall dealer about a month ago, they had it for a day and couldn't find anything wrong .
I noticed droplets of water around the header tank vent, so took a punt and replaced header tank and lid. Seemed ok after a 200 mile motorway journey, then did a 30 mile journey a couple of days later and the problem was there. Did another long journey and used a little coolant, but not much.
Since then it has got worse, until a couple of weeks ago after about 30 motorway miles the car came up with an alarm sound and message 'Reduced engine power' and I noticed the temp gauge was up a bit from normal (maybe 95°C instead of 90°C).
Pulled over and pooped the bonnet - coolant level slightly low. Left it for a bit then very carefully loosened the header cap - lots of hissing and boiling and the level dropped like a stone until the tank was close to empty.
Back to the Vauxhall dealer - they had it for a week, said they had tested everything - block test, road test, etc - and couldn't find anything wrong.
Still the only problem I could see was a drip from the header tank vent.
So, I took the car to a different main dealer a week ago - he ran the diagnostics on the car and said it needed a new thermostat. £300+ later, and the problem was still there. Back to the dealer today - after a couple of hours he called to say no fault found so I asked him to keep looking, and after another few hours he called to say they had done another bottle test and this one was positive (previous ones were negative). He said this means either the EGR valve cooler (£1000) or head gasket (£1600) and the only way to find out was to do the job, so which would I like to try first . He did say Vauxhall may contribute as a good will gesture, but they would have to do the work first.
I would have thought that from the amount of coolant the car is losing it would be really obvious if it was going into the exhaust? It still looks to me like a circulation issue - ie there is a hot spot somewhere and the water is boiling off through the header tank vent, so I called an independent Vx specialist to get a price for a water pump, however he said my engine (A17DTE) requires a special tool so is a main dealer only job to replace, and water pump parts alone is £350.
I'd be grateful for any thoughts / suggestions of anything to check / anything else to do before I put the blindfold on and give my credit card to the Vx dealer.
Cheers
Chris
Long post, but hoping someone can help me.
Got a strange issue with my mark 6 Astra J (1.7 EcoFlex diesel, 12 plate 80K miles) - it is using huge amounts of coolant but no sign of a leak.
The coolant leak has got worse over time, until now it gets through about a litre of coolant in 30 miles. The symptoms are that when reaching the end of a journey the coolant level in the tank would look ok, or appear to have dropped slightly. It was only when you restarted the engine after it has cooled down or remove the header tank lid that the coolant level would drop suddenly and majorly. Temperature was rock solid as normal at 90°C on the gauge.
No evidence of an external leak, oil looks ok (no mayonnaise), no evidence of water out of the exhaust, coolant in the header tank looks ok (no oil evident).
Took it to my local Vauxhall dealer about a month ago, they had it for a day and couldn't find anything wrong .
I noticed droplets of water around the header tank vent, so took a punt and replaced header tank and lid. Seemed ok after a 200 mile motorway journey, then did a 30 mile journey a couple of days later and the problem was there. Did another long journey and used a little coolant, but not much.
Since then it has got worse, until a couple of weeks ago after about 30 motorway miles the car came up with an alarm sound and message 'Reduced engine power' and I noticed the temp gauge was up a bit from normal (maybe 95°C instead of 90°C).
Pulled over and pooped the bonnet - coolant level slightly low. Left it for a bit then very carefully loosened the header cap - lots of hissing and boiling and the level dropped like a stone until the tank was close to empty.
Back to the Vauxhall dealer - they had it for a week, said they had tested everything - block test, road test, etc - and couldn't find anything wrong.
Still the only problem I could see was a drip from the header tank vent.
So, I took the car to a different main dealer a week ago - he ran the diagnostics on the car and said it needed a new thermostat. £300+ later, and the problem was still there. Back to the dealer today - after a couple of hours he called to say no fault found so I asked him to keep looking, and after another few hours he called to say they had done another bottle test and this one was positive (previous ones were negative). He said this means either the EGR valve cooler (£1000) or head gasket (£1600) and the only way to find out was to do the job, so which would I like to try first . He did say Vauxhall may contribute as a good will gesture, but they would have to do the work first.
I would have thought that from the amount of coolant the car is losing it would be really obvious if it was going into the exhaust? It still looks to me like a circulation issue - ie there is a hot spot somewhere and the water is boiling off through the header tank vent, so I called an independent Vx specialist to get a price for a water pump, however he said my engine (A17DTE) requires a special tool so is a main dealer only job to replace, and water pump parts alone is £350.
I'd be grateful for any thoughts / suggestions of anything to check / anything else to do before I put the blindfold on and give my credit card to the Vx dealer.
Cheers
Chris
stevieturbo said:
You need to find a mechanic with a brain. That does rule out most main dealers.
Really...if it's losing that much water, it shouldnt be difficult to test and find out where from and daignose it properly.
If anyone can suggest a good mechanic in the Southampton / Portsmouth area I'd be really grateful.Really...if it's losing that much water, it shouldnt be difficult to test and find out where from and daignose it properly.
Cheers
Chris
Pumaracing said:
The most likely scenario here is a very small leak into the headgasket.
Many thanks for the pointer and the explanation. After the last time I drove it, there was evidence again of coolant dripping (slowly) out of the header tank vent. I also noted that when I switched the engine off I could hear hissing from the vent - I grabbed some of my lad's bubble mix from the house and painted it onto the vent and it seemed to blow bubbles, as if it were over pressure rather than under vacuum?Bearing in mind the comments regarding main dealers, how easy is it to do a bottle sniff test? The dealer said the last sniff test was positive, and when I queried how this had not been picked up before he said that previous sniff tests had been negative. From your comment about the likelihood of a very small headgasket leak does this mean that it might be 'easy' to miss with a sniff test?
The return line (small bore hose into the top of the header tank) appears to be spurting quite a lot when engine is hot (as if aerated). Never paid any attention to this before so not sure if it is normal or not?
I am assuming a worn water pump or blocked radiator would show up as a high temperature on the gauge? I ran the car up to temperature and monitored the radiator hoses - the hose on the right hand side of the radiator (nearest to the water pump) got hot but the hose on the left hand side (nearest the thermostat) stayed completely cold. Not sure if this indicates anything other than I didn't leave it to run for long enough?
Cheers
Chris
stevieturbo said:
This is more aimed at tech guys, but they might be able to point you in the direction of a reputable and competent garage local to you.
http://www.bba-reman.com/forums/
Thanks, I will give them a try.http://www.bba-reman.com/forums/
Cheers
Chris
A bit more info - not tried putting videos on Youtube before but hopefully this will work. Both videos are with car idling at normal operating temperature indicated on the gauge after a short run.
Video of return line into header tank:
http://youtu.be/NWrG1rvP8aM
Video of drip from header tank vent:
http://youtu.be/BfRUkPr9vU4
Cheers
Chris
Video of return line into header tank:
http://youtu.be/NWrG1rvP8aM
Video of drip from header tank vent:
http://youtu.be/BfRUkPr9vU4
Cheers
Chris
Thanks for all the responses,
As mentioned, yes the header tank cap includes a pressure relief valve (rated 20 psi according to the label on it), and the vent is downstream of this.
Thanks to for the suggestion about the water pump. I was suspicious about this, and even more so when I asked an independent Vauxhall specialist about changing it - as well as specifying it was a main dealer only job o replace, he also commented that there had been a design change to the pump (though didn't go into any detail). Only thing that points me away from the water pump is that the heater is still getting good and hot?
Cheers
Chris
As mentioned, yes the header tank cap includes a pressure relief valve (rated 20 psi according to the label on it), and the vent is downstream of this.
Thanks to for the suggestion about the water pump. I was suspicious about this, and even more so when I asked an independent Vauxhall specialist about changing it - as well as specifying it was a main dealer only job o replace, he also commented that there had been a design change to the pump (though didn't go into any detail). Only thing that points me away from the water pump is that the heater is still getting good and hot?
Cheers
Chris
Thank you everyone for your responses.
Good points about the fluid venting from the header tank - there is no anti freeze residue evident - good idea about setting up a catch pot to see what / how much is coming out of the vent, though awkward to do as the vent is effectively part of the tank moulding.
I have run the system up at idle (for longer than the previous time), and this time the radiator hose temperatures seemed ok - I managed to scrounge a thermal camera from work and the inlet was about 80°C with the outlet about 60°C cooler. No other obvious hot spots around the cooling system (at idle at least)
Having dug into the cooling system design, the EGR valve cooler is fed by an electric auxiliary water pump which draws water from the inlet to the radiator and returns it to the radiator outlet (I would have expected the flow direction to be the opposite way round, but apparently not). Hence the diagnosis from the garage that it is either a head gasket or EGR valve cooler. If I could rule at least one of them out I would be happy.
What I am not clear on is (assuming a failure of the EGR valve cooler) whether there will be exhaust gas present in the cooler if the EGR valve is closed (ie is the EGR valve on the exhaust side of the cooler or the engine inlet side). This means I'm not sure if disconnecting the EGR valve would be a valid way of checking where the problem is? As per bearman68's post I could bypass the EGR cooler temporarily, but figure I don't want to risk causing damage.
The other thing I'm not sure of is the one long (200+ mile) trip I did when the problem disappeared. I'm thinking there must have been something different about that trip, but can't think what.
I'm also a bit concerned that pressure tests have (reportedly) not shown up a leak, and bottle tests prior to the last one have also been negative? Is the volume of coolant I am losing just so minor that the tests can be expected to be inconclusive?
Cheers
Chris
Good points about the fluid venting from the header tank - there is no anti freeze residue evident - good idea about setting up a catch pot to see what / how much is coming out of the vent, though awkward to do as the vent is effectively part of the tank moulding.
I have run the system up at idle (for longer than the previous time), and this time the radiator hose temperatures seemed ok - I managed to scrounge a thermal camera from work and the inlet was about 80°C with the outlet about 60°C cooler. No other obvious hot spots around the cooling system (at idle at least)
Having dug into the cooling system design, the EGR valve cooler is fed by an electric auxiliary water pump which draws water from the inlet to the radiator and returns it to the radiator outlet (I would have expected the flow direction to be the opposite way round, but apparently not). Hence the diagnosis from the garage that it is either a head gasket or EGR valve cooler. If I could rule at least one of them out I would be happy.
What I am not clear on is (assuming a failure of the EGR valve cooler) whether there will be exhaust gas present in the cooler if the EGR valve is closed (ie is the EGR valve on the exhaust side of the cooler or the engine inlet side). This means I'm not sure if disconnecting the EGR valve would be a valid way of checking where the problem is? As per bearman68's post I could bypass the EGR cooler temporarily, but figure I don't want to risk causing damage.
The other thing I'm not sure of is the one long (200+ mile) trip I did when the problem disappeared. I'm thinking there must have been something different about that trip, but can't think what.
I'm also a bit concerned that pressure tests have (reportedly) not shown up a leak, and bottle tests prior to the last one have also been negative? Is the volume of coolant I am losing just so minor that the tests can be expected to be inconclusive?
Cheers
Chris
Pumaracing said:
To the OP, there's a nice simple test you can do to throw more light on this. With the engine cold make sure the cooling system is full and just let the engine warm up at idle while you watch the expansion tank vent. This is an unthrottled diesel so there'll be plenty of combustion chamber pressure at all times.
If the vent starts blowing off and the coolant is definitely not boiling then you know it's combustion chamber pressure. You might want to turn the engine off from time to time so you can listen to the vent as well.
Hi, thanks for the suggestion - I ran the engine up idling from cold on Sunday. I shut down after 30 minutes and there was no evidence of leakage from the vent? I will check again but won't get the chance until the weekend.If the vent starts blowing off and the coolant is definitely not boiling then you know it's combustion chamber pressure. You might want to turn the engine off from time to time so you can listen to the vent as well.
Cheers
Chris
bearman68 said:
Mmmm you might well be right. Having said that, EGR pressure must be up somewhere about 3 bar I would think, plus there is a direct heating effect from the hot gas into the water.
I'm not saying it is the EGR, only that it is possible, and relatively easy to check. Head off, or EGR blank. No contest for me.
My personal little action plan would be
1) Temporary EGR removal. Check with long hard run, and sniff test. If fail then
2) Strip out the water pump for a good look.
3) Steel seal / leak blocker / chemical warfare.
4) Head off.
Bugger of a job to remove the head.
Thanks for the suggestions - I have ordered hose clip pliers so will try bypassing the EGR cooler by linking together the two cooler hoses and see what happens.I'm not saying it is the EGR, only that it is possible, and relatively easy to check. Head off, or EGR blank. No contest for me.
My personal little action plan would be
1) Temporary EGR removal. Check with long hard run, and sniff test. If fail then
2) Strip out the water pump for a good look.
3) Steel seal / leak blocker / chemical warfare.
4) Head off.
Bugger of a job to remove the head.
Cheers
Chris
andyiley said:
I am still leaning away from chg/head issues for the same reasons as stated before.
Sniff test pass, pressure test pass, no oil in water/water in oil. (Before anyone says anything, yes I do know these are rules of thumb & there are exceptions)
EGR I have no real experience of, so can't comment.
I am still leaning towards water pump not operating correctly. As said before I have come across the exact symptoms before (sniff pass, pressure test pass, no oil in water/water in oil, heaters working, temperature up on slow/short trip, fine on long/faster trip) Which turned out to be the pump impellor blades rusting away.
I am not familiar with your particular engine layout, is there any way you could rig up a temporary inlet & hose to the pump from a large pop bottle or something, to see how well the pump actually pulls in the water? Or better still on the return from the engine to see the throughput?
Thanks for your input. One comment - on the last visit to the dealers I was told it had now failed the sniff test - when I queried this saying they had told me it had passed before, they didn't have an answer. I've ordered a sniff test kit to check for myself.Sniff test pass, pressure test pass, no oil in water/water in oil. (Before anyone says anything, yes I do know these are rules of thumb & there are exceptions)
EGR I have no real experience of, so can't comment.
I am still leaning towards water pump not operating correctly. As said before I have come across the exact symptoms before (sniff pass, pressure test pass, no oil in water/water in oil, heaters working, temperature up on slow/short trip, fine on long/faster trip) Which turned out to be the pump impellor blades rusting away.
I am not familiar with your particular engine layout, is there any way you could rig up a temporary inlet & hose to the pump from a large pop bottle or something, to see how well the pump actually pulls in the water? Or better still on the return from the engine to see the throughput?
I don't think there is a particularly easy way of accessing the pump pipework direct - probably closest option is one of the radiator hoses (I'm thinking get a length of hose and feed it back up to the header tank?). Its a bit of a pain because (as far as I can gather) the water pump has an electric clutch and it only pumps water when the engine is hot. Any thoughts on what sort of flow rate a 'good' water pump should give?
Unfortunately popping the water pump out is not straightforward - a special tool is required to take the tension of the (auxiliary drive belt.
Cheers
Chris
Well, my ebay sniff test kit turned up and I got home in time to test, and pretty conclusive that there are exhaust gases present. Not sure why the initial tests by the garage were clear (maybe the leak has got worse since then) but now seems very obvious.
I think what has been throwing me is the electric clutch on the main water pump. Basically the water pump seems to cut in and out in a similar manner to the fan. Running it up to temperature tonight the hoses were all different temperatures (as if there was a blockage), then I heard the water pump click in and start pumping, seconds later all the hoses had come up to similar temperatures.
The EGR valve is mounted on the EGR valve cooler, so I think the only way to rule out the EGR valve cooler is to bypass it as previously suggested.
Cheers
Chris
I think what has been throwing me is the electric clutch on the main water pump. Basically the water pump seems to cut in and out in a similar manner to the fan. Running it up to temperature tonight the hoses were all different temperatures (as if there was a blockage), then I heard the water pump click in and start pumping, seconds later all the hoses had come up to similar temperatures.
The EGR valve is mounted on the EGR valve cooler, so I think the only way to rule out the EGR valve cooler is to bypass it as previously suggested.
Cheers
Chris
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