2.0 HDi 163 Head Gasket??

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chadderzj
Posts: 2
Joined: 30 Dec 2024, 10:21

2.0 HDi 163 Head Gasket??

Unread post by chadderzj »

I have a Peugeot RCZ 2.0 HDi 163 which up until recently has been amazing.

We are querying head gasket or EGR cooler?

Bit of background:
Car does not over heat, does not produce white smoke, does not loose coolant.
Car looses cabin heat on idle

The only loss of coolant is via the expansion tank when this pressurises too much. This coolant is not hot/ boiling.

Replaced Thermostat, heater matrix, flushed all pipes on short heating circuit (apart from EGR COOLER).
Problem still occurs
Done a sniff test changed colour so accepted there are exhaust gases.
For reference the EGR was mapped out a few years ago, but I think even if this valve is closed there are still exhaust gases passing through the unit itself, it’s just a short circuit?

So I think the next port of call is to do a compression test.
I have never done one on a diesel, can’t really find any answer anywhere but…
Do I need a special guage? I have a standard one used for petrols (straight on spark plugs)
Special tools?
Go on the injector or can it be done from the glow plugs?

Thanks
PaulC5
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Re: 2.0 HDi 163 Head Gasket??

Unread post by PaulC5 »

Cylinder pressure in a diesel is a lot higher than a petrol so your gauge may not go high enough or be strong enough.
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Stickyfinger
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Re: 2.0 HDi 163 Head Gasket??

Unread post by Stickyfinger »

And a small leak may not show....a "leak down" test will be better.....BUT, if the sniffer test shows a leak you will have a leak, maybe even just a small one.
Alasdair
Activa, the Moose Dodger
chadderzj
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Joined: 30 Dec 2024, 10:21

Re: 2.0 HDi 163 Head Gasket??

Unread post by chadderzj »

I have already done a sniffer test and shows presence of exhaust gases.

I wanted to totally rule out the egr cooler hence doing a compression test but if this won’t show, how do I rule the egr cooler out before pulling the plug on a head gasket?
Stickyfinger wrote: 30 Dec 2024, 14:17 And a small leak may not show....a "leak down" test will be better.....BUT, if the sniffer test shows a leak you will have a leak, maybe even just a small one.
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Stickyfinger
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Re: 2.0 HDi 163 Head Gasket??

Unread post by Stickyfinger »

Good thinking....
I would think by removing it and testing it off the car, you have to remove it (?) to remove the HG....so maybe then.

?? Apply a highish (30-40psi) pressure to it with air and test in a bucket of water, looking for bubbles ?
Alasdair
Activa, the Moose Dodger
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Muir
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Re: 2.0 HDi 163 Head Gasket??

Unread post by Muir »

You can do a compression test via the glow plug ports which will allow you to get accurate readings with the motor running.
It might not be possible on your specific engine depending on where the plugs are situated, since you'll need space for the gauge connector.
(Also be very careful with removing the plugs if you go this route, they can break giving you a whole new level of headache.)

Bought a set similar to this one to test compression on my Diesel Cruze, it worked very well.
Granted I had to custom fit the adapter with the right thread as it was a bit too long, but it was just a question of measuring it vs. the length of the glowplugs and cut it.
https://autofix.nu/produkter/8639-kompr ... KEQAvD_BwE

Mind you the cylinder pressure in diesels can easily reach 30+ bar so make very sure the adapter fits snugly and the connector is fitted proper before starting.