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Discussion Starter · #1 ·
Hi Guys,

i am after a bit of help if possible..... i have a 1.9 JDM unit in a car of mine, currently i am having chronic issues with over/under heating!!!

About 4 months ago the head was replaced, an injector seal was damaged and couldn't be repaired. Second hand head was sourced, skimmed and a 2 notch head gasket fitted along with new head bolts, cam belt, water pump and inlet manifold.

Recently it has started to blow water out of the header tank, over 2 days it will empty the header tank, so its quite excessive. It only does it under pressure, the header tank and cap are in good condition.

Connecting an obd reader i have managed to get real figures out of the ecu whilst driving.

Ambient temp was 9 degrees, car took ages to warm up, when it finally warmed the temp fluctuated between 72-85 degrees, and this was fast A roads.
Turned the heater on full blast at 28degrees and the temp dropped from 82 to 78 degrees very quickly.

Pottering around town at about 30mph the temp sat at 84 degrees, out on the motorway at 80 mph the temp dropped to 78 degrees.

Ran for 5 miles up the motorway temp dropped to 70 and then back up to 82, by the time I came off the slip road it was down to 75.

Pulled over and held the car on a fast idle (2000 rpm) for 5 mins, temp never moved from 80degrees

first thought was thermostat, removed it and tested it, opens perfectly, radiator flows water with no apparent blockage put it back on the car, refilled the water and ran it up to temp.

Again couldn't get it to rise above 86degrees, but this time I notice the rad was stone cold, the pipes rock hard and when I opened the drain plug on the rad the water was cold, but the engine was sat at 86 degrees!!!

with the hoses off and the engine running there is a flow of water out of the engine, so that would point to the water pump working.

the radiator fans never kick in, i dont think i have ever heard them, the temp gauge never moves from the middle of the gauge although my obd reader tells me otherwise.

Any suggestions?
 

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I assume you mean 1.9 JTD or JTDM? First thoughts: either an airlock or leaking head gasket.

The front coolant pipe - the metal pipe across the front of the head - has a bleed screw, to clear trapped air. With the header tank topped up, slacken that screw off until coolant runs from it, then tighten it. Then run the engine with the heater on to clear any more trapped air.

Otherwise, you probably need a block test kit, eg http://www.ebay.co.uk/itm/Block-tes...ines-original-BT500-leak-tester-/171632095441 to test for exhaust gases in the header tank. That would confirm a leaking head gasket is pressurising the cooling system.

EDIT: I suppose we shouldn't discount the possibility of a blockage somewhere too, eg a rag stuffed into a pipe then not removed on reassembly.
 

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Discussion Starter · #3 ·
Hi, yes it's a jtdm engine.

Did a "sniff" test tonight



On the left, a fresh sample from the bottle, on the right the fluid that had "sniffed"

I believe the head gasket is goosed judging by that colour :frown:


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That does look depressingly green.

Having just done my own head, that's not good news. Did you DIY or was it a garage job that might have warranty?
 

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Discussion Starter · #5 ·
I did it myself, so it looks like I'm pulling it apart again then.....grrrr


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The header tank pushing out the coolant was a dead giveaway the gasket is leaking. or the head is cracked ofcourse.

the temp gauge will point to the middle between 80°C and 115°C.
 

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Discussion Starter · #7 ·
So finally started to strip the engine down.
Head is now off, first thing I noticed there was a lip on the top of the bore


Looking close the bores look unscored however number 3 piston crown looks cleaner than the others, and when I poke about there appears to a bit of piston movement, have a look at the video

https://vimeo.com/161094401

Opinions?


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cold engines always allow some piston movemement. the pistons are aluminium, and expand at a faster rate than the cast iron block. Compare with the #2 cilinder.
 

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Just a thought, I've only got experience with petrol engines do its slightly different, but the boiling water test for a thermostat is not 100% fool proof. I've had thermostats fail which would still pass the boiling water test - they would open and close, but with not open and close fully, or be extremely slow to respond. The stat in my SEAT Leon failed this way recently it never quite completely closed, so the engine would run colder than normal, and take a long time to reach temperature, but on a long motorway run the temp would eventually stabilise exactly fall way up the gauge. If it opens or closes too slowly you cannot reach a stable temp. I'd definitely agree this looked like head gasket failure though.


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Discussion Starter · #10 ·
Thanks for the advice, it does seem like HGF and looking at this pic it seems that this was the culprit

Number 4 cylinder, what's worrying is that this is the block, I'm hoping the head gasket was faulty.

Now having stripped it I have noticed a few things, specifically about number 3 cylinder, the crown on the piston was very clean in comparison to the others

When I looked at the head the valves were very clean on number 3, but what really worried me was looking at the glow plugs

The one with brown staining is from number 3 cylinder, it appears diesel is getting up the glow plug and burning off.
All of this would imply that the injector is faulty. Which would support the bad fuel economy this engine gives, is there any way of testing an injector? Is this a common issue?

Thanks


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That piston is super clean because it has been scoured with coolant, c/o a HG leak.

It's normal for pistons to have some lateral movement in the bores, and bad if they don't - which would point to trapped rings.

You can check your bores for even wear by rotating the engine to the mid point (all pistons at the same height), then filling them to the brim with brake cleaner. They should all drain at roughly the same rate (+/-) over an hour or several. Of course you then have to oil the bores, and change the oil and filter before running the car...

Do make sure you get the right HG, there are different thicknesses depending on whether valve seats have been recut to compensate for skimming. Only buy from a specialist who can advise.

The torque procedure for the head bolts is unclear and cryptic in eLearn. Studs have to be lightly oiled and the holes must be cleared of all oil and water else you'll get a hydraulic lock/false readings. I used strips of rag wound round coat-hanger wire and it took me ages.

You can use the bolts up to 4 times according to Autodata.

The tightening sequence is normal and clear enough but you have to go around the sequence multiple times. IE
first pass to 35Nm,
second pass to 65Nm,
third pass +90 degrees,
fourth pass +90 degrees,
fifth pass +90 degrees.

This is extremely, worryingly tight and needs at least a 2' breaker bar. However it seems to have worked here.
 

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Discussion Starter · #12 ·
Thanks for the info Halftone,
I wasn't aware that the head bolts could be reused, I always thought angular torqued bolts were single use, thanks that's saved me a little money on this.

To my knowledge we didn't have water in the cylinders, we didn't have any water loss or steam from the exhaust. from what I could see it appears that the HGF was on cyl 4.

I will try the piston test, the engine is coming right out, sump removed and being cleaned and checked along with the oil pump. It's always been a "clacky" engine and I wonder if the oil pump is a bit lazy or the strainer is blocking

According to the documentation the engine/car has only done 63,000 miles!!

I have had JTDM engines that have 250,000 plus miles that are quieter than this one


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Discussion Starter · #13 ·
Mods, would it be possible to move this to engines section? Thanks


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Discussion Starter · #14 ·
Stripping the engine today, plan was to remove the sump, check, clean up and ready the engine for reassembly.
Taking the clutch off and noticed this
https://vimeo.com/163163239
Should it move that much or have I got a knackered dmf?

Then I got the sump off, cleaning it out and I found 3 of these

Does anyone know where they may have come from? I wondered if they were rocker related and had fallen down through due to a snapped cam belt in the past!!



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Don't know about the DMF as I have never played with one but although the picture isn't clear your clutch pressure plate fingers (springs) don't look to be in very good health.
 
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