Padge

Good morning all, after a bit of advice please.

I was driving home yesterday when the top up coolant warning came on. Carried on down the road a bit and the car felt odd to drive. Didn't seem to be changing gear picking up speed etc. As I approached a roundabout car stalled, wouldn't start again.

Checked the coolant level and it was empty, poured some water in that I had in the boot and steam was coming from around the engine. Ended up calling breakdown and getting the car towed home. While I was waiting I did a quick Google and read on some of the vans that engine will cut out when overheating. Tried starting the car once it has cooled before the recovery truck came and car started fine.

Been unable to try and source the leak as of yet, but mainly wondering is the engine likely to have been damamged or would the action of the engine shutting itself off protect it?

Thanks in advance for any replies, hope you all manage to have a good seasonal holiday, Padge

JettaRed

iTrader: (1)

Did you notice the water temperature gauge during this time? Did it deviate much from ~93°C?

I've never heard of automatic engine shut-off due to overheating, but there's lots I've never heard of. That would be an amazing failsafe. Overheating can cause the head to warp, leading to coolant and oil mixing, loss of compression, and other problems. Before driving much more, you need to top off the coolant with a 50/50 mix of the appropriate coolant for your car, and then find and fix the leak.

Padge

Thanks for the reply. I didn't notice the temperature to be honest. Once I had put a bit of water in after it had stopped i looked at it was around the usual middle range. Car isn't going to be driven till I find the leak.

This car has had various coolant parts break in the past, a elbow into the cabin, and the fuel filter housing. Not sure whether to check them first or look elsewhere

TimC300

In my opinion I would say that its good that you did not notice the car over heating, the temp way above normal. Hopefully its just a hose and not something internal in the engine. There may be an engine cutoff that goes off the coolant pressure senor, I have no idea.

Do you see coolant on the ground? Grab a flashlight and start looking in the engine bay, remove the air cleaner to inspect under it. Feel around the floor inside on the passenger side to see if its the heater.

I just looked in my operators manual and it says if the coolant does overheat the warning light will come on and also the car will make an audible noise informing you. So if you dont remember hearing it it may not have overheated, and just lost coolant.

Padge

Just for those that are interested and replied.

Found the leak. A pipe just off the fuel filter housing had come off and was pouring out all the coolant. Pipe back on, fluid topped up and all seems fine.

Pic added incase anyone else has problems as a pointer.

TimC300

Just shows that what may seem like a big issue can be as simple as a loose hose.

If its one of the hoses im thinking of it doesnt seem like a really secure way to attach things, looks like it may work its way off over time. Which happened in this case. Quite a few posts on coolant hose issues with the cdi. Probably a good idea to go around and check them all.

JettaRed

iTrader: (1)

Guys, I appreciate the pics, but they are too up close to know what I am looking at. Perhaps include pics of where they are on the car. Thx.

TimC300

I rather enjoy playing find that location based on extreme close-up photos. I don't have or ever worked on a cdi so its extra fun.

I simply posted a photo of the fuel filter housing which shows how the coolant hoses just slip on and held with a spring clamp. Also from my searches it appears the fuel filter housing itself is a fairly common source of coolant leaks and needs to be replaced.

From the photo i was assuming its in this area:

TimC300

May be hose# 270?

gl540man

Hello PEagle,
I am having the exact scenario - mysteriously vanishing coolant - in a 2016 GL450. Car is running just fine. No oil color change or white smoke. It's been troubling me for the last 3 months or so now. Here is what I have done...
1. Hoisted the car in a repair garage 2 times - one with dye injection, inspected every corner with purple flash light - no sign of leaks.
2. Ran the scanner. Showed a Coolant sensor malfunction. So I replaced the reservoir (as the sensor is inside the reservoir). - no luck.
3. Change the Reservoir cap (brand new) - no luck.
I am absolutely lost. I just cannot think where the heck this coolant going. I have to fill up the coolant in every 6-8 days. In my case though, if I do not run, there are no leaks. But if I run the care - even short distances, within 6-8 days the coolant level drop and a message displays on the dash.