strange cooling issue !!!!!

[tony gee]

I thought I'd do a separate thread in this section.

so i picked up a 2012 C204 coupe yesterday with the 1.6 M274 engine. on the way up the M6 i noticed the temp gauge slowly rising till it went into the red !!! so pulled over and within a few seconds of stopping the gauge started to drop, so back on the motorway and was fine for a few miles and then did it again, this time into a service station and let it cool down so i could check the fluid level, that was fine so back on the road and ok for about 10 miles or so and then it started to rise again !!! but for some reason i turned off the heater ( didn't have A/C on) and within 3-4 seconds it dropped back to normal ??? later on i put the heater back on and same thing it started to rise. turned of and dropped straight away so left the heater off.
got on the slower A roads and put the heater back on and it was perfect the 35 miles to my house, you can drive it all day long at none motorway speeds and its perfect, it seems to only do it at 70ish MPH but not at 50 MPH or less !!!!! very strange ???
I plugged my scanner in and found a P02170 code ( coolant sensor) so I'll get that changed and also the thermostat housing done under warranty.
just can't understand why it does it at speed with more air flow and the heater on ? back in the old days that would keep an engine cooler !!!!

 

[tony gee]

bit of an update, spoke to the seller (garage) and they said get it booked in to my local garage and get them to sort it, and what ever it cost the seller will pay for it all. they are very helpful, makes a pleasant change

 

[AMGeed]

^ Sounds like a decent trader if he comes through with payment.
We are quick to condemn poor service, but good customer service is often taken for granted.

 

[tony gee]

^ Sounds like a decent trader if he comes through with payment.
We are quick to condemn poor service, but good customer service is often taken for granted.

yeah i was really happy with how me n the Mrs where treat, the boss wasn't their but when i foned up today i spoke to the main man, and will fix any issues it has. theirs a few !!!!!! I was seriously thinking about getting my c200 back as that had no problems at all and its 5 years older !!!! but i know the C204 will be sorted now, plus I love it.
just look at it

 

[StMarks]

Fwiw I'm thinking perhaps an airlock in the heater matrix may be able to manifest those symptoms ?
I wonder if they're going to let you know the outcome, after they've fixed it for you .

 

[W1ghty]

Is there any danger that this overheating issue could have caused long term engine damage even if they underlying fault now gets fixed ?

 

[tony gee]

Fwiw I'm thinking perhaps an airlock in the heater matrix may be able to manifest those symptoms ?
I wonder if they're going to let you know the outcome, after they've fixed it for you .

yes they will, the boss is a decent guy and i always take my cars to him for MOT's. plus he's a biker

 

[tony gee]

Is there any danger that this overheating issue could have caused long term engine damage even if they underlying fault now gets fixed ?

i really don't think it is over heating, been around cars for long enough plus why would it do it at motorway speeds with the heater on and not in slow traffic with no heater on !!!!!
ive had cars that are getting hot when stuck in traffic jams, all i do is raise the engine rev's a little and watch the temp gauge drop back to normal. it just pumps the water round quicker and cools it down.
plus my car is showing a fault with the temp sensor on my scanner

 

[E55BOF]

Could you not have changed the temp semsor yourself and saved a lot of hassle?

 

[tony gee]

Could you not have changed the temp semsor yourself and saved a lot of hassle?

yes i could but the seller is insisting that they fix it, but it looks like all the electrical issues it has is down to the small battery in the boot as its fecked.

 

[ernie]

These engines are prone to thermostat failure, but it's a 3 hour job due to the position of the 'stat. At MB rates you could be looking at north of £500. So definitely let them fix it!

Ernie

 

[tony gee]

These engines are prone to thermostat failure, but it's a 3 hour job due to the position of the 'stat. At MB rates you could be looking at north of £500. So definitely let them fix it!

Ernie

im not convinced its an over heating issue, im sure its an electrical thing. the aux battery is dead and giving all kinds of problems, new battery on charge as we speak.

 

[tony gee]

as said in another thread, the battery fixed it, everything working as normal, its a joy to drive now.