Last post on Nov 17, 2010 at 10:20 AM
You are in the Volvo V70 Maintenance & Repair
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Volvo V70, Volvo V70 R, Engine, Wagon
#62 of 88 leaking heater core
Jan 07, 2009 (3:31 am)
I want to add that while antifreeze is toxic, having a leaking heater core which releases antifreeze into the heated air stream is not nearly as hazardous as, for example, an exhaust system leak which releases CO (carbon monoxide) into the passenger compartment.
Concerning my 2004 V70 (base model 2.4L non-turbo), which we bought new in Oct 2003, the heater core is not leaking. When I had it in for an oil change, I asked about the heater core because I had had it leak on my 1989 Dodge Caravan, and I was relieved when the garage told me that, if necessary, the heater core in the 04 V70 could be replaced without removing the entire dashboard.
This V70 has less than 40 kmi on the odometer. But I am thinking that at over 5 years in service it may be time to replace the coolant. At a recent oil change I asked the garage (independent Volvo specialist) about this and they told me that there was no specified replacement interval for the coolant on this vehicle.
Antifreeze consists of two main active ingredients:
(1) the antifreeze component. This is normally the toxic ethylene glycol (but may be non-toxic propylene glycol, which is more expensive and may not be as good for heat exchange.)
(2) the anti-corrosion additives. There are several different sets of anti-corrosion chemicals, but none of them lasts indefinitely. Also some of the different types are incompatible with others. The longest warranty I am aware of (excluding antifreeze for commercial trucks) is 5 years or 100,000 miles. I have read that that Volvo uses Zerex G-05 in the OE fill and this should be good for 5 years or 100 kmi.
Each of the different types of antifreeze is dyed a different color and when bought in labeled retail containers Zerex G-05 is, I think, orange or pink. But when the auto mfgrs buy coolant in bulk from the coolant manufacturers they can and do request their own dye color. So the fact that Volvo coolant is green does not mean that it is not G-05. Volvo does not state in the manual what type of antifreeze it uses, but only says to use the Volvo antifreeze specified for a given Volvo.
When the anti-corrosion chemicals become exhausted then vulnerable components like the radiator and heater core will corrode.
One measure of the effectiveness of the anti-corrosion effectiveness of the coolant is to determine the pH of the coolant. A year ago I used swimming pool pH test strips* to compare the pH of the coolant in my 2004 V70 to my wife's 2007 XC90. They were about the same, if I recall correctly it was a little over pH 8 for the '07 XC90 and a little under pH 8 for the '04 V70. As the anti-corrosion chemicals become consumed the pH becomes lower and lower.
I plan to ask about a coolant replacement at my next service.
*You can get special pH test strips for testing auto coolant, but the local auto parts store didn't have them and had never heard of this. While walking my dogs I happened to find a container with two unused strips which had probably be dropped by a pool servicing technicians. We do not have a swimming pool.
#63 of 88 Re: leaking heater core [jim314]
Jan 07, 2009 (2:17 pm)
Thanks Jim, due to weather issues I have not yet been able to take a good close look at the heater core. The interior floors do not appear to be wet (or smelly). In looking under the hood, there is some powdery substance on the connector between the rubber coolant hose and where the metal pipes go through the firewall. It is greenish/yellow - perhaps this is where the leak is. Could this leak, however, be the cause of the poor defrosting and interior smell when the defrost/heater is running? I had a coolant system flush not all that long ago (within the last 9 months), so, the coolant should be fine, except to the extent that water has been added on occasion (rather than coolant). I really appreciate the input. The local Volvo dealer ust quoted me $800 to replace the core (parts and labour).
#64 of 88 Engine or accelerator problem.
Feb 08, 2009 (7:14 pm)
I have a 2002 V70 Wagon.with 116,000 miles. It is like brand new and one of the finest cars I have driven. I did experence a bit of a problem as follows.
In the mountains of western NC parked on a steep drive, I started to back down the drive. The engine suddenly went to full acceleration. I jammed the gear shift into park, pulled on the emergency, all to no avail. Went down the drive, accelerating all the way. Hit a railroad tie marking the drive, blew out the left front tire, hit the main road where I had to make a greater than 90 degree turn up hill (going backwards). The blown tire came off the rim and dug into the asphalt. The car finally stopped without rolling over. There was a steep drop on my left that, praise be to God, we did not go over. Put the spare temporary on and drove away with no apparent damage. Has anybody had a problem with a run away engine or did I do something that may have brought about this event?
#65 of 88 Re: leaking heater core [torme]
Feb 09, 2009 (7:07 am)
You might just have a leak at the connectors on the engine side of the firewall, i.e. the heater core might not be leaking internally. The leaked coolant would then get swept into the airstream and carried into the air intake for the passenger compartment. Alternatively, the leaked liquid coolant might then be getting around the seal and into the passenger compartment. If it is leaking there, then you might be able to see the leak.
To determine whether this is a possible source of the leak could take some examination and knowledge of the controls of the heating system. But even without much knowledge you might be able to see a leak just examining the connections at the firewall with the engine on and warmed up. In my 2004 non-turbo V70 the connections of the two heater hoses are clearly visible on the driver's side of the the firewall (two approx 1" diameter hoses with crimp connectors to right angle black plastic connectors.) Have a look!
A leak at the connections might be a lot cheaper to repair than replacing the heater core. It could be that one or both of the two heater hoses could be replaced (or even just one or both of the connectors); getting new sealing elements might stop the leak. You can get a leak analysis.
Why did you get a cooling system flush? Were you having problems with the cooling system? It could be that the flush caused this leak.
#66 of 88 Re: leaking heater core [jim314]
Feb 17, 2009 (10:46 pm)
thanks for responding and for your suggestions. My mechanic purchased the heater core (per my request) and plans to install it tomorrow, but I will take your suggestions to him, and I will have him will check for leaks first - he's an honest guy .
I did not have the radiator flushed. My mechanic doesn't think it will need it. I can't figure out how to see my post so I don't remember my wording, but I might have meant the second problem the car is having, which is with the transmission. so i may have asked about a transmission flush.... the transmission did a weird thing one day where I was stopped in traffic, with foot on brake. then when I stepped on the gas, nothing happened. as if it was in N. then the electronic letter flashed between D and N and R. I turned off the engine and restarted and it was fine. My mechanic read the code and I think it said clutch slippage. He thought the fluid was dirty. Volvo dealer thought the fluid looked "wrong". wrong color - too pink for having 78k miles since it was last drained. and wrong smell-not synthetic. So they recommend flushing it. Volvo charges $400!! another Volvo dealer charges $250. synthetic fluid is pricey, but I read on some blogs that Mobil JWS 3309 fluid is the same for much less $. any advise here is greatly appreciated! thanks again. Arlene
#67 of 88 Re: leaking heater core [sheraotwp]
Feb 18, 2009 (5:02 am)
To read previous posts you can go to previous pages in the page list at the bottom of the page. But if you want to follow a trail of replies select the light grey text at the top "Replying to: . . ." then do the same on that post, etc.
Modern cooling system practice is to simply drain and replace the coolant with fresh. In the past some people did perform pressurized flushing of the cooling system. It had been found that such treatment often caused more problems than it solved, so drain and replace is the way to go (unless you had some specific blockage and were very careful not to apply too much pressure in the flush).
A given auto tranny requires a specific type of fluid. Personally I would go with the Volvo fluid which was originally in the vehicle. I don't have any knowledge as to whether the Mobile AT fluid that you referenced is an acceptable substitute for the original equipment (OE) Volvo one or not.
#68 of 88 Re: Engine or accelerator problem. [donhunt]
Feb 18, 2009 (8:45 am)
I have not yet received a reply, though research has led me to many similar incidents m one involving the death of a 22 year old daughter driving her father's car. Hear this, Two days after the acceleration down hill problem I had a reoccurance.. Same hill and drive. This time in addition to putting the car into park , pulling on the emergency brake and pressing the regular brake with all my strength, I also turned off the key. I missed the drive this time and crashed through trees and down a steep bank crashing into the bank on the upside of the ditch. My glasses and the keys were found in the back seat. Thank God no injuries.
#70 of 88 Re: leaking heater core [torme]
Feb 18, 2009 (1:49 pm)
Here is a discussion of transmission issues:
Concerning the cooling system, in your post referenced above, you did state that you got a cooling system flush. And you also state that the defrosting performance is not good, as well as there being an odor. One effect of a leaking heater core is that volatilized ethylene glycol (the main ingredient by weight in the antifreeze) condenses on the insides of the windshield and on the windows as an oily feeling film. (Wipe it with your index finger and then rub the finger and thumb together.) This would definitely be classified as poor defrosting performance.
#71 of 88 Re: leaking heater core [jim314]
Feb 18, 2009 (10:22 pm)
I'm confused.... the discussion you referenced seems to be talking about engine oil. I was referring to transnmission fluid. Does anyone know if the Mobile JWS 3309 is synthetic transmission fluid that is compatable with Volvo V70 2001 2.4L? I can't believe the price the Dealer is asking $210 just for the fluid!! I love the car faces