Hi folks.

 

Ive posted a couple of times before, need some advice.

 

I look after my friends Fabia 8V MPI, at least until he learns DIY. I run B5.5 Passsats myself for my liking, though a small TDI Fabia for a workhorse is tempting me, something with a relative of the VW AFN engine.

 

This is about a 2000 Fabia MPI AZE code engine.

 

The car has had a main dealer fitted Temac replacement HG something like 2 - 2.5 years ago due to a blown HG

 

I recently replaced CTS and tested coolant temps etc with VCDS and everything is working as normal.

 

Then I flushed and cleaned the coolant because the car had very pale and murky coolant, not so much as obvious emulsified oil but very opaque in the expansion tank and obviously much diluted coolant as it had corroded the sensor pins enough in the coolant tank to cause a permanent coolant level alarm. At this point no emulsified oil observed at all in oil cap. It appears either not enough G12 was in the system or major top up dilution had occured as the drained coolant had a very faint oxide trace/colouration in some of it. Rad and block were flushed, and back flushed with a hose thoroughly.

 

At the time of flushing I refilled coolant with a 60/40 mix of water/G12+

 

Then it lost its water pump gasket (rotted out and disintegrated) so I replaced the water pump + gasket (new part) and again refilled 60/40 water/G12 + At the time of changin water pump didnt seem too bad and there wasnt really much laquering or oxidadion in the pump chamber so generally the coolant jacket is probably ok.

 

Perhaps a month later Ive just replaced his starter motor (bad bearings and then also stuck solenoid).

 

While doing so I noticed the coolant is again very opaque, again no oil emulsified in oil cap or significant visible emulsified oil residue in coolant tank, even after standing for a day or two.

 

Hes not losing coolant that he is aware of and Ive told him what to watch for, theres no over pressurization issues in the cooling system, VCDS checks out on coolant temps.

 

Oil levels are good and it doesnt seem to be making any noticeable losses of oil

 

Im wondering about re-torquing the Temac gasket or a HG replacement. On revving hard the engine has a slight and brief whistle/shriek sound I havent yet tracked down. It could be any of the following though so far Ive got no visual inspection proof of anything :

 

Dry bearing (unlikely)

Passing exhaust gasket or joint

Passing intake gasket

Head crack

Head Gasket

 

My questions :

 

Re-torque values? (I believe 20nm then 2 quarter turns is procedure) - what does that make the final nm value for a re-torque check?

 

Re-torque pattern?

 

Best replacement HG make?

 

I know that a skim and pressure test is called for either on existing head or verified on a replacement head, I also know that after this much time a re-torque probably wont help but its worth a try, even if it makes an audible change in the shriek sound.

 

The car is doing something like 27 mpg extra urban, and its a relatively new driver, but even so I think thats a little low even for an MPI and I am doubtful a slight intake or exhaust leak would dent fuel economy considerably.

 

I know its only a 44kw engine but it feels like there should be a litttle bit more than its currently giving.

 

Advice and suggestions welcome.

Edited 28 January, 201412 yr by mindriot

Anyone?

Cylinder head bolts: Stage 1. 20Nm Stage 2. Angle tighten 90⁰ Stage 3. Angle tighten a further 90⁰ Cylinder head nuts; 20Nm

Tightening Sequence

 

As for the make of head gasket, I'd just get an OEM one from TPS.

 

Hopefully someone will be able to help further.

I seriously doubt that a re-torque will achieve anything at all, I'm completely mystified by the coolant contamination but I do suspect an intake air leak somewhere causing the whistle you hear when revving, possibly leaky vacuum pipes on a car that age.

 

Try and find the air leak, correct it and reset the ECU to default map, I'd ignore the coolant issue for now since it poses no threat.

yup exessive air being sucked in will make it run rich, looking at the lamda switching when warm will help.

also dosent g12 change colour when certain impurities have been mixed with it ?

Thanks folks.

 

Ive looked at the vac pipe - seems ok (only 1 on the mpi afaik) - at some point might look at silicone peplacements.

 

Any coolant reaction or contamination bothers me, just shouldnt happen on a healthy engine. However the MPI does seem an odd little engine.

 

Experience tells me coolant issues and lost mpg means head related issues.

 

I was really after the final nm torque value for head bolts if its known, cant slack and retighten on an old gasket.

 

What measurement blocks in vcds give lambda values and is there a fabia guide for vcds.

Edited 29 January, 201412 yr by mindriot