Coolant Loss - no obvious visible leaks. Any tips? (1 Viewer)

[1150A]

I have been smelling coolant after driving our 2001 LX470 and shutting it off. I don't smell it in the cabin.. yet, only when I'm outside the car after shut off near the front of the hood. Found my reservoir tank empty the other day. Filled it back up to full , drove 40 miles and then it was down to the minimum line.

I've checked my dip stick and oil looks fine. I am not blowing white smoke out the exhaust. I'm checking all the hoses but so far I have not found any signs of leaks. My heater Ts look good and were replaced last year and water pump 2 years ago.

Any suggestions on what else to look into?

I'm a noob mechanic and learning as I go. Really hope it's not signs of bad head gasket. Trying to do as much as I can at home before bringing it into a shop. Any tips would be greatly appreciated!!

EDIT: took to a mechanic today and they did a pressure test. Did not find leaks but he said he could smell faint smell under timing cover. Thinks it could be water pump and suggest to do timing belt too. I just did this 25K/1.5 years ago with Aisin parts so this is a little concerning.

 

[awesomeissquid]

There are some heater hoses under the truck that go to the rear heater. My guess would be either those are leaking or the heater tees have a leak that might have been missed.

 

[Boston Mangler]

Drain oil, see if milky, if so, headgasket

also, pull plugs and smell them

 

[GTV]

From my experience the most common place they can leak is from the o-ring on the coolant crossover pipe just below the throttle body.

 

[Jack90210]

There are some heater hoses under the truck that go to the rear heater. My guess would be either those are leaking or the heater tees have a leak that might have been missed.

Came here to say exactly this. Look above the passenger side cat for the rear heater hoses. Also, pull the splash guard on the bottom and look for pink staining.

One of the nice things about the red coolant is the pink powdery traces that it leaves.

 

[abuck99]

Help us to Help you - if you start with providing a brief service history of anything relevant to the concern- such as- How long since the last coolant system flush? How old is the radiator? It’s it original or a replacement ? When last were heater Ts replaced, water pump replaced when? What are your operating temps? Any other work done last few months ?

Cold check coolant level in radiator tank- remove cap ( after 8hrs cooled off) where is fluid level? Top of neck or below ?

 

[Not So Yeung]

Under intake manifold

 

[1150A]

Help us to Help you - if you start with providing a brief service history of anything relevant to the concern- such as- How long since the last coolant system flush? How old is the radiator? It’s it original or a replacement ? When last were heater Ts replaced, water pump replaced when? What are your operating temps? Any other work done last few months ?

Cold check coolant level in radiator tank- remove cap ( after 8hrs cooled off) where is fluid level? Top of neck or below ?

Last coolant flush was at 190K about 1.5 years ago. At this time I also did timing belt, water pump, heater ts, spark plugs, starter by a independent shop. I brought in Aisin timing belt kit that I bought off Amazon. Operating temps I'm not sure exact but it was right in the middle.. never got much higher than that.

No work done to the car at all other than oil changes by me.
I just took it to a new to me shop (moved states) and they did a inspection + pressure test. They mentioned it is holding pressure but could faintly smell coolant under timing cover. They said they suspect it could be from water pump. They also noted in diagnostic that I did not have timing belt sticker so suggested to replace that as well (I didn't initially tell them I had that replaced at 190K). When I called back to tell them that, they did again mention that the mechanic suggests taking it apart and going over it all because if coolant got onto timing belt then it should be replaced.

Curious to hear your thoughts on this. New to me mechanic and it's not exactly a cheap job to do water pump/timing belt all over again. They quoted a NAPA kit which doesn't sound as appealing either. Parts come in on Monday for them and thats when they begin. They also are doing inner tie rod replacement which they suggested as well (I do think these need to be replaced though due to the shaking while braking)

I'm tempted to see if I can get there in the morning and possibly get a second opinion . Curious to hear what everyone thinks on this?

 

[LWA55DAL]

If it’s the water pump, and it could be, then you should see it coming out of the bottom of the crank cover on the crank shaft. I have used the AISIN kit on both of my 100’s, but unless you really know what you are doing - it is simple to miss a bolt or miss a torque setting.

I’d suggest pulling all the covers under the vehicle, getting it hot, and looking for leaks. The leak should be obvious given the amount of coolant loss if it hot.

My 2 cents, but if you can smell it - it’s in the engine compartment.

 

[AlpineAccess]

Use a flashlight and look behind/below the heater Ts where the one heater T hardline connects to the crossover pipe. If someone yanked on the heater Ts when putting them in that crossover pipe can leak as well.

A little coolant steaming off smells like a lot of coolant; whereas a lot of coolant leaking but not steaming/burning off smells like a lot of coolant

 

[abuck99]

I would not let them do a TB service just yet- and definitely no to Napa parts (strike one for your new shop). As remarked above any measureable coolant leaks under timing cover from water pump area would be wet under crankshaft (harmonic balancer pulley) at the weep hole.

is the radiator the original from factory-( 215k miles on it) ? Ever replaced the cap? Since topping off the coolant bottle, have you continued to top off during the past week? What is the cold coolant level you see under the cap - full to the brim of neck or just above the fins?

Smelling coolant could simply be from the low level in overflow bottle-but suspect a pinhole leak in the radiator or seal leak where the tank is crimped to the radiator body. I would look all around the radiator very closely- for pink powdery evidence of dried coolant.

 

[1150A]

I would not let them do a TB service just yet- and definitely no to Napa parts (strike one for your new shop). As remarked above any measureable coolant leaks under timing cover from water pump area would be wet under crankshaft (harmonic balancer pulley) at the weep hole.

is the radiator the original from factory-( 215k miles on it) ? Ever replaced the cap? Since topping off the coolant bottle, have you continued to top off during the past week? What is the cold coolant level you see under the cap - full to the brim of neck or just above the fins?

Smelling coolant could simply be from the low level in overflow bottle-but suspect a pinhole leak in the radiator or seal leak where the tank is crimped to the radiator body. I would look all around the radiator very closely- for pink powdery evidence of dried coolant.

Good to know. I'll hold off on the TB service but have them do the inner tie rods. Unfortunately I'm not so mechanically inclined so it's been pretty difficult figuring out what to do / where to look. Like anyone though, I'm really just not trying to screw up the LX here. Was really worried that it was head gasket failure and got nervous to drive it any more.

If I'm losing 3/4 of coolant in the over flow on a 40 mile drive, should the leak be pretty obvious to find? Seems like a lot. I looked in the hood best I could and also under the car and didn't find any signs of any moisture. And to be quite honest, I don't know exactly how long I've been driving with the overflow at minimum.

As for the radiator, it is likely original from factory. I purchased the car at 120K and am second owner. Not sure if others are like this but I do notice the plastic top which makes me assume it is original/oem. The cap I have not replaced..I will definitely try that next. I topped the coolant bottle once, then did that 40 mile drive, then I topped it off again and just dropped it off at the shop. They mentioned it was full when they checked it but that was a short 5 mile drive. Both times I noticed the coolant bottle was low, I did check the radiator and noticed filled to the fins.. maybe a little higher. About an inch under the rad cap I'd say.

One thing I should note -- when I did the initial timing belt replacement + water pump the mechanic asked if flushing and replacing with green coolant is OK and I said yes so we've been using the green stuff.. not sure if that makes any difference.

 

[cruiserdan]

<snip> I brought in Aisin timing belt kit that I bought off Amazon <snip>

Read this:

Possible fake AISIN water pumps in AISIN timing belt kits

I wanted to save folks time, so here is another drop in the bucket for my contribution to the forum. I'm a preventive maintenance fanatic and preorder everything before I actually do it, it's a bad habit that comes costly sometimes. I've had instances where I wait too long to open boxes or...

forum.ih8mud.com

 

[CJF]

If I'm losing 3/4 of coolant in the over flow on a 40 mile drive, should the leak be pretty obvious to find?

So OP:

Are you still driving it? Are you monitoring coolant levels? Could be as simple as the radiator wasn't totally filled, then you filled the overflow and that moved to the rad. That is: maybe there's no leak and you're not even continually losing coolant.

 

[1150A]

Read this:

Possible fake AISIN water pumps in AISIN timing belt kits

I wanted to save folks time, so here is another drop in the bucket for my contribution to the forum. I'm a preventive maintenance fanatic and preorder everything before I actually do it, it's a bad habit that comes costly sometimes. I've had instances where I wait too long to open boxes or...

forum.ih8mud.com

Definitely saw that and am considering it for sure -- which is why I'm on the fence of letting this shop do the replacement again. But obviously the $$$ spent here on both is sorta making me second guess things.

This is the one I ordered:
Amazon product ASIN B008EEYWKI
I woulda thought ordering from the 'Aisin' store was legit.. but who knows.

 

[1150A]

So OP:

Are you still driving it? Are you monitoring coolant levels? Could be as simple as the radiator wasn't totally filled, then you filled the overflow and that moved to the rad. That is: maybe there's no leak and you're not even continually losing coolant.

That would be awesome -- and certainly something I considered. But again sorta just freaked out thinking it was HG issue and dropped it off at shop. So no currently not driving it.. but I think plan here is to hold off on the TB replacement, let them do the inner tie rods, and continue to figure out this coolant thing on my own.

With them doing a pressure test and saying its holding pressure makes me believe this coulda been the situation ^. If that was however the case though.. and excuse my dumb-ass-nes here but I haven't checked my coolant reservoir for a loooong time. It coulda been low for quite some time. But again.. the coolant smell is/was new.

 

[Bisho]

I’d start by filling the radiator to the top and getting a new radiator cap as mentioned before. Often the little rubber hose connecting the overflow bottle to the radiator neck leaks at the neck. You can pull it off, trim 1/2” off with a scissor and push it back on. I also put a small zip tie on the end for insurance.

 

[abuck99]

Good to know. I'll hold off on the TB service but have them do the inner tie rods. Unfortunately I'm not so mechanically inclined so it's been pretty difficult figuring out what to do / where to look. Like anyone though, I'm really just not trying to screw up the LX here. Was really worried that it was head gasket failure and got nervous to drive it any more.

If I'm losing 3/4 of coolant in the over flow on a 40 mile drive, should the leak be pretty obvious to find? Seems like a lot. I looked in the hood best I could and also under the car and didn't find any signs of any moisture. And to be quite honest, I don't know exactly how long I've been driving with the overflow at minimum.

As for the radiator, it is likely original from factory. I purchased the car at 120K and am second owner. Not sure if others are like this but I do notice the plastic top which makes me assume it is original/oem. The cap I have not replaced..I will definitely try that next. I topped the coolant bottle once, then did that 40 mile drive, then I topped it off again and just dropped it off at the shop. They mentioned it was full when they checked it but that was a short 5 mile drive. Both times I noticed the coolant bottle was low, I did check the radiator and noticed filled to the fins.. maybe a little higher. About an inch under the rad cap I'd say.

One thing I should note -- when I did the initial timing belt replacement + water pump the mechanic asked if flushing and replacing with green coolant is OK and I said yes so we've been using the green stuff.. not sure if that makes any difference.

As others indicated- the radiator must be filled to the top of the neck where it’s trickling into the overflow. If it’s not it will keep drawing from the reservoir until it’s level. It may have never been burped/purged properly from your last TB service- and you’re now just noticing it. You might have to check under the cap more than once to be sure it’s stayed topped off- do this first thing in the morning when it cool.

Once the radiator is full to top, then add coolant to the overflow- halfway between low and high mark- get a sharpie and mark that halfway level. That is your new cold check level. Start monitoring the level in morning and after you get it full operating temp- make a mental note of the hot high level- it’s really a basic thing but tells you a lot to the health of the cooling system if you monitor the overflow regularly.

About Green- Red- Pink coolant: some will say it doesn’t make a difference- I disagree. First note is that cheap Prestone green coolant should be flushed more frequently- 24 months or 24k miles- compared to Toyota Red LL “long life” every 3yrs or 36k and Toyota pink- SLL2 “super long life” 4 yrs or 50k miles. Coolant looses its lubricity over time and also its anti corrosion properties- I trust Toyota coolants to last at least as long as the recommended service interval and maybe beyond. Not confident in anything else for my truck. YMMV

 

[beatle_bayly]

In addition to checking oil and smelling the plugs, also compare the plugs (and if possible, check the top of the pistons). I've found that if coolant is leaking into the combustion chamber you'll often see one plug/piston crown has been steam cleaned compared to the others, and may have a tinge of coolant colour on the insulator.

 

[1150A]

Got car home from shop. Still need to do some testing here but so far I've noticed:

- Still smell the coolant when I pop open the hood for ~ 5 mile drive.
- Did notice a drip as shown here. Not sure if mechanic did something but I don't think I noticed this before. Any ideas? Will keep an eye on it. Will be doing a longer drive on it tmrw