Coolant Leak - TDV6 2.7 D4

[Lukeis]

Hi Guys

I had the 'coolant level low' light come on today so when I got home I put my head under the car to see if there were any leaks and noticed quite a lot of coolant over the lower engine near the passenger side front wheel.

I have two pics as follows;

1) taken from the top, for reference you will notice the battery box in the corner so this is the front passenger side of the bonnet. The highest point where there is leaking coolant is quite close to the top of the engine from the pic (assume then the leak is quite high?)

2) taken from under the car, shows how much red is splashed around.

Does anyone have any tips on what it might be or is it impossible to say?

I'm obviously praying it is nothing too serious!!

http://www.aulro.com/afvb/attachment.php?attachmentid=115821&stc=1&d=1477474467

http://www.aulro.com/afvb/attachment.php?attachmentid=115820&stc=1&d=1477474467

[Ralasa]

I had similar leak in mine , was the water pump seal o ring , just replaced the water pump, easy job

[Lukeis]

Thanks Ralasa.

Was that a DIY job or did you take it to the mechanics? Do you remember how much it cost?

[Ean Austral]

The normal place is between the heads where the plastic housing has 2 hoses coming in the front and is bolted to the block, but the coolant usually ends up in the valley between the heads and doesn't end up where your coolant is showing.


The water pump is on that side and could be a culprit or the hose you see clamped on the front of the timing cover is a coolant hose and could have rubbed thru and have a pin hole.


Best bet is remove the covers on the top and over the radiator and start it up and see if you can see it.


PS you will need to fit the air trunk back on from the air cleaner housing. keep your hands and head away from the fan.


Cheers Ean

[BMKal]

My recent coolant leak turned out to be coming from the bleeder screw in the top of the coolant reservoir. I suspect that someone may have over-tightened it at some time, and the head of the screw split off the body - was still in position until I touched it with a screwdriver, when it fell completely off.

Coolant ran down the side of the reservoir (of course on the side that you cannot see), then along the hose from the bottom of the reservoir (which is where I initially thought the leak was coming from), and then out the bottom of the car. Puddle on the shed floor was almost directly beneath the leak, but a bit further back. Looking under the vehicle, the signs were very similar to yours immediately after driving the vehicle, as wind had blown the leaking coolant further back.

https://www.aulro.com/afvb/images/imported/2016/10/115.jpg (https://postimg.org/image/c6al5ujfd/)

https://www.aulro.com/afvb/images/imported/2016/10/116.jpg (https://postimg.org/image/ljo8g77mr/)

https://www.aulro.com/afvb/images/imported/2016/10/117.jpg (https://postimg.org/image/ehkz6a6ux/)

[Ean Austral]

Thanks Ralasa.

Was that a DIY job or did you take it to the mechanics? Do you remember how much it cost?


You will need to remove the fan, not a hard job but remember its left hand thread , then remove the belt , use a ratchet into the tensioner and slip off the belt, the water pump is held on by 3 bolts, 1 at the top just under the timing cover, and 2 at the bottom, - think the Mercedes emblem -


Down side is you will loose coolant when you remove the pump , and its very hard to catch it.


Cheers Ean

[Lukeis]

Ean, I think you have guessed it.

I went back and had another look, the hose you mentioned which attaches to the timing cover is wrapped in some sort of fabric which is clearly wet and this is the highest point so on closer inspection it looks like where the hose bends is actually rubbing on the pulley for the belt which sits below it. (see pic)

This is supported by the fact the left side of the pulley is like a polished silver colour as if it was rubbing on something whereas the right side of the pulley is a dull rustic colour as expected so I'm 90% confident thats the problem.

I have no idea how to replace that hose tho so I'll have to have a better look in the morning or off to the mechanics for a speedy fix as I need to take the car on holidays on friday..

thanks again for your help!

http://www.aulro.com/afvb/attachment.php?attachmentid=115823&stc=1&d=1477479626

[Ean Austral]

Yep that hose runs very close to the pulley , the hose goes across to the opposite side , but where it goes from that bend I am unsure, but don't think it will be a easy access hose. I reckon the battery box may have to come out or maybe it can be accessed from the wheel arch but it wont be easy me thinks. -


Good luck with it and be thankful it happened before you left, as it wont be an easy fix on the side of the road.


Cheers Ean

[Lukeis]

Interestingly, the mechanic here in Sydney is unable to get the hose before the weekend (I'm taking the car away) so he is going to cut the hose where the hole is and replace the bend with a short copper pipe and re-clamp the hose on to each end..

outside the box thinking, I like it!

[Tombie]

Short term ok.. maybe..

Prefer to see a barb-barb fitting there.
And get the copper out ASAP - another metal in the system will help with corrosion.

What ever you don't - don't let it overheat or the price will be phenomenal..

[Ean Austral]

A copper elbow would most likely be a better option there , I think if it was me I would be making sure plenty of it feeds inside the hose , like atleast 25mm each end and good quality hose clamps used. If you could find it with the barb on each end as Tombie say's even better.


There are 3 clamps that hold that hose in place , your mechanic may need to move the hose further across to get it away from the pulley , especially with a couple hose clamps close by.


I think ( but not 100% sure ) the D2 may have had a hose that had a solid elbow in a similar spot.


Cheers Ean

[scarry]

Lucky to catch that before a major expense and failure,hope it all works out.

For me,i wouldn't go anywhere until it is fixed properly,to much to risk.

Good post for others with the 2.7;

I noticed that hose was about 3mm from the pully on mine,the clip that holds it up and away from the pully was loose.

It is something i check regularly.

[PerthDisco]

https://www.aulro.com/afvb/images/imported/2016/10/8.jpg

Checked mine and it is scarily close! The restraining clamp was also loose. It tightens into a plastic housing so does not go tight. The adjacent mount under the pipe to the left does go tight. Thinking a cable tie might be useful here.

[Ean Austral]

https://www.aulro.com/afvb/images/imported/2016/10/8.jpg

Checked mine and it is scarily close! The restraining clamp was also loose. It tightens into a plastic housing so does not go tight. The adjacent mount under the pipe to the left does go tight. Thinking a cable tie might be useful here.

If you remove the fan cover you will see that hose follows the timing cover across the front of the engine and there are another 2 clamps holding it. You can move the hose across which lifts it clear of the pulley and re tighten the other clamps.

Cheers Ean

[PerthDisco]

If you remove the fan cover you will see that hose follows the timing cover across the front of the engine and there are another 2 clamps holding it. You can move the hose across which lifts it clear of the pulley and re tighten the other clamps.



Cheers Ean



Did as instructed only to find the mount where the hard pipe enters the rubber pipe was missing bolt altogether [emoji30]. Probably from when timing belt was done 2 years ago.

[Lukeis]

It is scary how close the pipe is to that pulley, would be worth taking 2 minutes to have a look if you own a D4 (not sure if it is the same on the facelift model).

Happy to report I gave the car a good run on soft sand over the weekend and it performed without a hitch (or temperature rise)!

[Ean Austral]

https://www.aulro.com/afvb/images/imported/2016/10/8.jpg

Checked mine and it is scarily close! The restraining clamp was also loose. It tightens into a plastic housing so does not go tight. The adjacent mount under the pipe to the left does go tight. Thinking a cable tie might be useful here.


If you look in the same spot but on the opposite side ie drivers side hidden under the intercooler hose there is a coolant hose that's very close to a bracket that is bolted to the timing cover and the hose can rub on it. Mine had a slight indent in it from where it had, I cable tied some old water hose around the coolant hose where it could touch the metal bracket


Cheers Ean