My coolant reservoir is 3-4 inches lower after 60k miles. Normal or not?

[Threxx~]

My wife's 05 4runner V6 is about 7 months away from her 7yr Toyota extended warranty from being out, so I have been watching out for anything I might need to get fixed under warranty.

A few days ago I noticed that the coolant level was so low that it's barely high enough to reach the point in the reservoir where the tank 'widens out' from its narrow neck.

I went back to my pictures of it when it was brand new and noticed the level was much, much higher. Although I also noticed that I took these pictures when the engine was completely warmed up.
https://lh3.googleusercontent.com/_Rs8M5953Xyc/TLWnimUTO-I/AAAAAAAACTQ/zPYBnQPRLx0/s720/DSC00937.JPG

So I took notice of the coolant level the next time our 4runner was fully warmed up and would estimate it's about 3 or 4 inches lower in the reservoir than it is in this picture even though we've never had anybody, to my knowledge, touch our cooling system.

At this point I have not determined if the coolant loss has occurred gradually over the last 6 years and 60k miles or if it might be a more sudden thing, so I've marked the level off and will watch to see if it continues to lower quickly or gradually.

But my question is if this happened very slowly over the last 6 years and 60k miles of driving, could it be considered normal, or is it still something I should try to figure out before the warranty is up?

If I bring it in to the dealer is it something where they're going to tell me nothing is wrong? The only other issue I had with my 4runner they tried as hard as they could to claim nothing was wrong until I proved otherwise.

 

[DaveS]

They should have topped it up as part of routine maintenance - I would guess its due to be changed based on age alone. I would have them do a coolant flush and refill - that way, if there is a leak somewhere it will probably show up more quickly before your warranty expires (if it's just a hose I think its not covered under warranty by the way)

 

[KB084RUNNER]

Take an engine oil sample that has 3-5000 miles on it and send it to Blackstone Labs and they will tell you if there is any coolant in the oil which would indicate a head gasket leak. Cost $25. If you go on the Blackstone website and register they will send you the necesary sample kit for free.

I do that test 5000 miles before any warranties are up on my vehicles.

 

[Threxx~]

They should have topped it up as part of routine maintenance - I would guess its due to be changed based on age alone. I would have them do a coolant flush and refill - that way, if there is a leak somewhere it will probably show up more quickly before your warranty expires (if it's just a hose I think its not covered under warranty by the way)

I've done all routine maintenance myself so far but haven't touched the cooling system. I'd think if the coolant system is sealed that it shouldn't technically be losing even a drop of coolant. But I also don't know if the V6 4runner uses a sealed or open system.

Yeah I think you're right about the hose not being covered. It's possible even a leaky water pump would not be covered under the extended warranty... I'll have to check.

I thought when I read the owner's manual that the coolant isn't supposed to be changed until 100k miles but I can't remember if there was a time deadline on there.

I'm really thinking about taking the 4runner in to an independent shop and pay them to find everything they possibly can that's wrong with it and then bring it in for warranty. I just don't trust my local dealer to go to any effort to find any additional warranty work... they seem to want to avoid doing warranty work when at all possible.

 

[Threxx~]

Take an engine oil sample that has 3-5000 miles on it and send it to Blackstone Labs and they will tell you if there is any coolant in the oil which would indicate a head gasket leak. Cost $25. If you go on the Blackstone website and register they will send you the necesary sample kit for free.

I do that test 5000 miles before any warranties are up on my vehicles.

Good idea! I forgot about them. I did send a sample to them many years ago for a different vehicle.

I'm actually due for an oil change right now. 7500 miles since my last change. I use Mobil 1 and a back stock of the old discontinued high end Nippon Denso Japan-made oil filters so I go with a slightly extended interval. Is 7500 miles too many or are you just saying I want to make sure I have at least 3k on the oil?

I was under the impression that if coolant is leaking into the oil that oil will also be contaminating the coolant, and the coolant, at least in the reservoir, looks as good as new (like you see in that picture I posted). Did I get the wrong impression about that?

I'm thinking maybe a slow leak from the radiator or water pump or a hose. But yeah if it's a head gasket then I DEFINITELY want that taken care of on their dime.

 

[ALLEGRO]

I am not completely sure that you have a problem. There is going to be some loss to evaporation no matter how "tight" the system is.

I would just monitor it, look for leaks and get an idea of how long you can go before you have to add. The summer should be a time of higher usage, but again, it may just be evaporation.

 

[Threxx~]

I am not completely sure that you have a problem. There is going to be some loss to evaporation no matter how "tight" the system is.

I would just monitor it, look for leaks and get an idea of how long you can go before you have to add. The summer should be a time of higher usage, but again, it may just be evaporation.

OK I didn't realize coolant evap was normal on a sealed system. I guess it all comes down to whether it lost that 3-4 inches in the reservoir very recently or just slowly over the last 6.5 years of ownership.

BTW I noticed you're in Memphis.:thumb3:

 

[the4Rdan]

I am not completely sure that you have a problem. There is going to be some loss to evaporation no matter how "tight" the system is.

I would just monitor it, look for leaks and get an idea of how long you can go before you have to add. The summer should be a time of higher usage, but again, it may just be evaporation.

I agree. The filler caps in my opinion aren't really all that "tight." My 4R has 55k and my wife's '07 Corolla has 51k on it. Both had dropped about the same level you indicate and needed to be topped off last week.

 

[DaveS]

Did not realise you were maintaining it yourself - I would top it up and then like others have said, monitor the level for a while. The oil test coming up to warranty expiry is an excellent idea as well.