23 replies to this topic

[Steve.i.am]

My car's been running hotter than usual. At the same time this started a coolant leak appeared on the water pump. The pump has been changed. It still runs hotter than normal. Temp fluctuates 90-96 on normal driving. 

 

The coolant is getting what looks like oil in it - inside coolant header tank:

 

 

The oil on the other hand looks clean and no mayo on oil filler:

 

 

 

Having read up various threads etc it seems it could be head gasket, or oil cooler. I know HGF is quite rare on Z22SE. If it were oil cooler could this cause it to run hot? If there is a little oil leaking into coolant from the oil cooler I'd suspect that wouldn't have much effect on coolant temp? More likely HGF?

 

My car really doesn't want to go to Zandvoort next week does it...

 

[jonnyboy]

Being a k series Elise owner I have to say it does look like the beginnings of hgf but as you rightly say it's very very rare on the VX...

[fezzasus]

Oil cooler!

[siztenboots]

dishwasher tab in there and flush it out is that new coolant when the pump was done?

[Bargi]

Is the coolant tank pressurising? I'd go with oil cooler, there's a thread of mine with pretty much the same symptoms. Get onto the wreckers pronto of it is cause they're £600 new

Edited by Bargi, 25 July 2014 - 01:53 PM.

[Kieran McC]

Steve your HG is on the way out ,I would change asap before Zandy any way just to be on the safe side, If you can pick up a oil cooler as well you are covered

Edited by kieranmcc, 25 July 2014 - 01:59 PM.

[siztenboots]

tank is supposed to pressurise to raise the boiling point , it will hold 15psi if the cap is good, whereas your oil will be much higher ~60psi+

[Steve.i.am]

Yeah the coolant (or a lot of it) was new from pump change. This is result of couple of hours driving. It had pushed some coolant out of the cap, but I've just replaced the header tank & cap and when I checked the cap wasn't tightening down properly so have put the old cap back on which tightens properly now. Tomorrow morning I can try removing the coolant hoses from oil cooler, join together, run it up and see if oil appears out of the cooler water ports. Is it accessible from underneath with under tray off?

[slindborg]

http://www.demon-twe...er-water-cooled

[vocky]

it is possible that the oil entered the coolant system when the water pump failed. 

 

The only z22se cylinder head gasket failures occurred when the engine was ran with no coolant, so it's unlikely to be the head gasket.

 

I would add half a cup of washing powder to the coolant system, run up to temp and then replace the coolant. That should wash out any oil.

 

If it reoccurs then the oil cooler is worth replacing next.

[Steve.i.am]

Cheers for all replies

http://www.demon-twe...er-water-cooled

Cheers   

it is possible that the oil entered the coolant system when the water pump failed. 

Good point. Car is still running hot though. Come to think of it I've not seen evidence of hot running on other oil cooler failures.

[Bargi]

What do you mean by hot running? So you changed the water pump, could you have disturbed the head gasket? Does the expansion tank pressurise at all after you key it cool down?

[Steve.i.am]

What do you mean by hot running? So you changed the water pump, could you have disturbed the head gasket? Does the expansion tank pressurise at all after you key it cool down?

Before it always ran at a rock steady 89 degrees on normal driving. Now it runs between 90 and 96 or more when driving along. Temp goes up very quickly going up hills. It got to 99 today driving along at 40mph up a hill. When stopped it gets to 103 really quickly before the fan comes on. I know it's hot weather at the moment but it never was like this before I had the water pump leak. Before it'd take quite a long time stuck in traffic to exceed 100 deg, maybe 10 mins or so. Now it does this in a minute. I didn't change the water pump myself but the head is not disturbed at all during that job. Yes the header tank pressurises but that's normal. I'm not aware it's pressurising any more than normal but have no way of actually testing that.

[CHILL Gone DUTCH]

Could you have abut of a air lock in there

[Bargi]

Is the expansion tank pressurised once it's cooled down? A symptom of HGF can be pressure after it's cooled down because of exhaust gases getting into the coolant

[Steve.i.am]

Could you have abut of a air lock in there

   System was apparently bled but yes could try bleeding it again

Is the expansion tank pressurised once it's cooled down? A symptom of HGF can be pressure after it's cooled down because of exhaust gases getting into the coolant

Right I see. I'll check that out. Cheers guys.

[CHILL Gone DUTCH]

Hard left hander when engine is hot, let a massive gulp of air out of mine last year the air must of been there for over a month

[slindborg]

Personally I'd be happy with 90-96 deg running....

[peteslag]

Can you not just do a sniff test of the coolant to illuminate HGF?

[Steve.i.am]

Yes a sniff test is needed. I couldn't find anywhere local to do it today. I'll look into getting a kit from somewhere. However things are looking a little more positive.. Today I flushed the cooling system. Twice. Once with dishwasher tab, then again with rad flush. Took off header tank and cleaned all the gunk out of it. Re-filled the system and bled it lots. Went for 2 hour drive in 27deg ambient. Temps much more stable to be honest. 89-92. No sudden heating up going up hills. The coolant and header tank were clean after the run. No signs of any more oil in coolant yet. Perhaps vocky was right in that the oil in the coolant might have come from when the old water pump failed. Thinking it may have gunked up the system making it less efficient? I'll monitor it and try & do a sniff test.