Coolant Thief!

M

mad_mackem

Member
 bristol
Morning all,

i wrote sometime ago that i had a coolant leak, which was obvious because of the big puddles on the drive and i could quite clearly see the drips dropping. i took the underpan off the car so i could see more clearly what was being left on the drive. now however the drips seem to of stopped and i dont see anything on the driveway anymore, yet every morning when i check the coolant level the tank is empty, has anyone got any ideas?? the only options i can think is dodgy thermostat/temp sensor which is pushing too much water through the system, iv got a pin hole leak somewhere, or every night somebody is lifting up my bonnet and syphoning out the coolant out of my car! appreciate this isnt a z4 specific problem, but if anybody with a bit more knowledge than me can suggest what may be happening or a way to identify it i am all ears!

Cheers

Andy :driving:
 
Andy - not wishing to be a prophet of doom but could be a head gasket blown and coolant is leaking into the engine. Check the oil to make sure there's no mayonnaise effect caused by coolant water mixing with the oil. Pressure check of each cylinder may identify a blown gasket as well. Other than that it's got to be a thorough check of all the pipework, odds on its a minor pipe leak. Fingers crossed.
 
X2 possible head gasket. Take it in for check, there's a quick and easy chemical test of the coolant to detect the present of exhaust gases. The longer you drive it, the more damage is done.
 
Has the engine temp gauge ever gone above normal? Did you drive it while you knew it was leaking? HGF is only likely if you tick both of those questions.
 
Whatever the issue may be I think if it were me I would resist driving until I had resolved the issue. As 'incompatible' if it is the HG then there is potential for significant damage by further using the engine. Just a precautionary measure.
 
hi guys thanks for the responses,

i have been driving it while its been leaking but iv been topping it up regularly as i thought it was just a leak in a pipe somewhere, head gasket hadnt occured to me :-s

the temperatures never been anything other than normal,

not really sure what to do now, is it possible i might of done something to cause the head gasket to fail when i was doing the vanos fix?
 
Before you start to worry mate, do what AlanJ said in the first reply to check for signs of HGF... It maybe nothing too sinister.
 
Morning all,

right i checked the oil this morning and there was no sign of any hellmans, it all seemed pretty normal.

I have had to drive the car this morning, but im planning on giving it a good looking over this weekend, and trying to check all the pipes etc, is it worth me sticking some radweld through the system aswell?

cheers

andy
 
NO - don't add any chemicals to the system - if you do have a HG failure (or a crack in the cylinder head - BUT highly unlikely....) then you will just be introducing additional chemicals into the engine and causing more issues. Here's a link which explains several tests including the check for Co2 in the coolant.

http://repairpal.com/testing-for-head-gasket-failure

Get these done at a local garage at least they will eliminate (hopefully) or confirm the problem. Another thing to do after you have driven or (although I wouldn't until I had eliminated the head gasket issue) is to drive it and then park it over newspaper. Leave it for a couple of hours or longer and then check for any damp patches on the newspaper which may help identify the location of the problem.

Just one more thing if you are topping up the coolant do it with the right coolant 'mix' - if you just use water you are gradually diluting the coolant mix which will also potentially cause problems.
 
Hey Andy, well first things first, give it a good, and i mean GOOD check, best while its hot and running and get some mates round too. Jack the car up, look under, cabin heaters on etc. Check the Coolant Temp Sensor and Thermostat too:
http://forum.bmwcarmagazine.com/viewtopic.php?p=888044&sid=3bfde65a247167e85e93f4f20aa2d540

If you really cant find it, and i know some people hate the stuff, but as a last resort you can try Radweld (Id personally recommend K-Seal). I was dubious... My old VX220 had a cracked head that literally gushed out water into the spark plug hole. 1 bottle of K-Seal, wait 2 mins with a hot engine and bam, the thing stopped! That lasted me 5000miles including 2 trackdays until i decided to change the Cylinder Head haha! :rofl:

I was so impressed with it, i actually emailed K-Seal to see if they wanted a written account of how happy i was. I was kindly declined by the Managing Director saying that his Lotus Elise Racing Team (Which run K-Series Engines with HGF and K-Seal) were proof enough! Good stuff :thumbsup:
 
One way I have checked for head gasket failure, (And it proved correct on all 9 different cars) is to start the car from cold, let it idle for 30 seconds and switch off. Remove the expansion bottle cap and if it is pressurised then the this pressure is coming from the cylinders. The system should not pressurise until the water is heating up, if it is doing it whilst cold and after a small run, then likely you have a blown gasket. Also the hoses become very stiff, normally you can squeeze them even when hot.
I have changed headgaskets many times, mostly Fiats, some Saxos and a Lancia. Always proved conclusive and always fixed afterwards. I have never had white smoke from the exhaust but always overheating, heater blowing cold and water loss.
No doubt someone will beg to differ, but I am sharing my actual experiences, and this method always proved it for me.
 
thanks for the help guys,

going to get it jacked up on stands and try everything suggested to try and identify the leak.

unfortunately i have just been topping up with water, as i didnt think there would be much need for antifreeze in the summer temperatures, i have got a bottle of blucol u that i can put through it though if this is more advisable?

it just seems weird to me that the i could see the car dripping coolant before, but now its stopped dripping but still losing water. is it possible that the temp sensor might be faulty and is causing the thermostat to release more water to keep the engine at what it thinks is normal temp?

Cheers
 
m-m,

Afraid just adding water in warm weather is not the answer. The antifreeze mix BMW uses is specifically designed for the engine to keep the engine at an optimal operating temperature in all conditions (hot and cold). The antifreeze element just means that it has a much lower freezing point than ordinary water so is safe in UK winter conditions and will not freeze and crack your radiator etc. The chemical additives also increase the boiling point so that unlike pure water it won’t boil over. In addition it contains corrosion inhibitors to prevent internal corrosion as it circulates around the engine.

Diluting it (your antifreeze) with water has an adverse effect on all these critical elements – find out what the problem is and get you cooling system flushed and refilled with the proper solution – like oil these things are the life blood of your engine. AND not in favour of mixing diffrerent antifreeze mixes in the same engine - yes it can be OK but that's just me, like adding a different oil as a top up to the original.
 
Look - you've got to stop driving this car until it's fixed......

You're diluting the coolant that as Alan notes is itself bad and have been doing this for a long time.

Just refilling the expansion tank does not get water back into the system and remove air locks, etc. Only as it cools will it pull water back in. You can easily wreck the engine this way.

If it's a hose or external leak it will only get worse and for the level of water you're getting through it would be very obvious as steam in the engine bay, wet carpets, water dripping off the undertray, etc. If one fails then you're in big trouble at the roadside.

If it's internal then it does not always go into the oil and can go to the cylinders - that won't self cure. I'd def do gookah's test

IMHO you should take it to a specialist and get the system pressure tested and the engine compression tested as a starting point. I really hop it turns out to be a hose clamp and simple fix, but consider the price of a new or engine rebuild if you continue to use it.
 
cj10jeeper said:
Look - you've got to stop driving this car until it's fixed......

You're diluting the coolant that as Alan notes is itself bad and have been doing this for a long time.

Just refilling the expansion tank does not get water back into the system and remove air locks, etc. Only as it cools will it pull water back in. You can easily wreck the engine this way.

If it's a hose or external leak it will only get worse and for the level of water you're getting through it would be very obvious as steam in the engine bay, wet carpets, water dripping off the undertray, etc. If one fails then you're in big trouble at the roadside.

If it's internal then it does not always go into the oil and can go to the cylinders - that won't self cure. I'd def do gookah's test

IMHO you should take it to a specialist and get the system pressure tested and the engine compression tested as a starting point. I really hop it turns out to be a hose clamp and simple fix, but consider the price of a new or engine rebuild if you continue to use it.
Click to expand...

ALL OF THE ABOVE - especially STOP USING IT UNTIL FIXED OR PROBLEM DIAGNOSED
 
done gookahs test, and the expansion tank didnt pressurise and the hose s were still squeezeable.

i did notice a puddle coming from the middle of the car the other day and iv take some photos of where i think its leaking from, will upload photos this evening.

going to get the car booked in as soon as i can.
 
Hi all

appologies but i have moved house and been away in the last month so barely had any access to the net.

i am happy to report that the coolant leak has now stopped, and i am rather embarrassed to admit what it was....

i stuck the car into my local indy (wheelbase in bristol) and they found that when removing the vanos unit i had removed a bolt from the thermostat housing which i hadnt re fitted when re installing the vanos! i did have a spare bolt but i couldnt see for the life of me at the time where it went. the indy was excellent and flushed the system and installed a new bolt FOC.

i am still slightly puzzled as to why there was no puddle on the floor, but since the works were done the coolant has held its level perfectly!

so at the end of all this it was a rather embarrisingly simple solution, but if the biggest expense is a bit of humility then im a happy man!
 
Excellent news! Maybe a good idea to name the Indy as they certainly seem kind! People are always looking for decent garages to goto :thumbsup:
 
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