Intercooler Weekend

[moorgate]

Ok, got all my bits together. Sunday's weather sounds OK (tomorrow is lost, unforch.). Batteries in all the torches. Stripped off the fan assembly today, and the I/C hoses. Fair amount of lurking old oil inside those; I am going to go for the coolant drain option, on the basis that it doesn't look any harder than taking all the other gubbins off to avoid it. Got extra-size catchers and a big fat water tank type thing to keep it in while doing the deed.

So far, the only oddity is that all the hose clamps on the I/C tubing and the bolts for the fan assembly don't seem especially tightly done up. Not the first time I've come across loose nuts n bolts on the Rescue Dog, which makes me suspicious that it might have been headed for the crusher at some point and then was, err, re-commissioned with a pile of bits from a less fortunate car.

So tomorrow it's up on the axle stands and off with the front undertray panel, and have at the main event! At least, for as long as I can pretend that I will be "only another five minutes..."

[Simon Jones]

Welcome to the intercooler weekend club . Did mine on previous XC a couple of years back. It's a bit fiddly but not difficult. Headlamp removal was not required but took them off as both wiper motors needed replacement and it probably made access a bit easier.

[moorgate]

I am hoping not to be that drastic - coming in from the back not the front, draining out the coolant. Pix probably tomorrow, since I have been caught spanner-fondling already today!

[moorgate]

and an update... my word, that's a nice little chance to cut your fingers to ribbons with one false move!

Observations: I am doing a modified Haynes procedure. This means, taking the "risk" of draining the radiator as payback for not taking the whole of the front of the car off. In practice, I have found that the radiator drain is pretty easy - the only risk to it really is that the nylon drain plug is tight and has to be undone with a ring spanner - you will round it off with pliers.

The key breakthrough, for me, was figuring out where and how to support the aircon condenser. Access is pants, really, to any of it's bits because it's right at the front of the stack of 3 radiators, and if your intercooler needs replacing then one of the symptoms of that is it growing innumerable sharp ragged bits, making access to the condesner harder and harder.

In the end, I took a careful look at the pipes that lead to the condenser. These are hard-mounted at the condenser end, and connect to soft flexi hoses quite close to the engine. In particular, the nearside pipe makes a u-bend, right beside the intercooler N/S air pipe. This is bad, because it's in the way - but it's also good, because as you can see in my pic, it's ideally placed (and strong enough) to take a luggage strap hanging from the air-box!

At the other end there's another metal pipe, completely hidden a few cm further down from the "5NM" cap that pokes up through the slam panel when everything's in place. It makes a somewhat tighter u-turn; it leads down to the receiver/dryer canister, and there's no soft rubber pipe runs involved. I got a big fat cable-tie round this and up to the slam panel, by propping all three rads up on the big poly box I used to catch the coolant and spreading them out a bit.

The key trick to getting the rad and the intercooler out from any direction, it seems to me, is to drop the O/S of the rad and intercooler right down to the ground first. To do this I had to unbolt the wiring loom that crosses between the engine and the body at the OSF - it hangs up the intercooler inlet fitting otherwise. If you try to take the two out purely downwards, then that condenser pipe I mentioned will foul the NS pipes on both intercooler and rad: the only way I could see (and did it) is to lift the NS end of the two rads with the OS end firmly on the ground. Then everything comes out smoothly, the aircon rad sits well supported, and even your shoes stay dry!

So in the second pic you can see a goosed IC close up. The second rail which should of course be the same shape as the others is entirely circular in section; I suspect it is almost entirely full of oil. The water rad was quite oiled up at the centre just where this part of the IC sat, and the condenser is also oiled almost all the way across the bottom 10%: so even though I couldn't get a hiss out of the IC once it was out of the car and I was blowing into it with the outlet pipe blocked, I don't think there's any doubt it's the culprit.

HOWEVER.

In takling everything to bits, I found that the MAP sensor (on the NS port of the IC) was utterly soaked in oil. Bit of careful cleaning shows that the active bit looks like a little yellow resistor or thermocouple: how that measures pressure, I dunno. But I am willing to bet that it doesn't measure pressure so well when covered in black goop! I suspect that oil leaking from the turbo makes the MAP under-read, which makes the wastegate open late, causing the turbo to overboost - and blow the IC.

Tomorrow, some epic cleaning, possibly involving wobbling back on the Moulton from Screwfix with a gallon of de-greaser: I will probably have the very very oily looking Turbo bottom pipe off and the EGR front pipe too, clean the whole lot up, and waggle the new IC back on with the rad. Piece of cake!

[Rooster]

Just taking the front off is alot easier,

Can have bumper and slam panel off in 45 minutes and only need 3 sockets 8mm,10mm and 13mm, oh and a torx 25

I did a friends S80 at home and didn't even bother jacking it up

[Simon Jones]

I tend to agree that bumper off and withdrawer the I/C from above without draining the coolant is the easiest method.

[chammyman]

Originally Posted by moorgate

In takling everything to bits, I found that the MAP sensor (on the NS port of the IC) was utterly soaked in oil. Bit of careful cleaning shows that the active bit looks like a little yellow resistor or thermocouple: how that measures pressure, I dunno. But I am willing to bet that it doesn't measure pressure so well when covered in black goop!

The yellow bit is the thermocouple and measures temperature, the pressude transducer is in the rectangular bit, if you look t it from above you can see into the sensor.

its dual function, temp and pressure.

I also pull the front end off and out the top like most others. I have a ramp and its still the easiest way.

[moorgate]

okay, all back together. Everything's nice and quiet, no more hissy-hissy - off for a test drive in a bit.

Putting the new assembly back in without the front off definitely qualifies as a pain! Aligning the retaining bolts all the way through the rad, the IC and the condenser is a proper challenge when you're doing it under the slam panel. And remember to put the radiator vent pipe to the header tank back on *before* starting on the connecting up of stuff - it's well out of reach back there.

The only way I could get everything jiggled in was to get the support under the three parts first, then get my hand round them by reaching all the way down behind the rad. Jiggling is then possible with that hand, while the other whacks at the long bolts to get them near the threads (which are on the condenser).

[cheshired5]

Originally Posted by chammyman

The yellow bit is the thermocouple and measures temperature

Is there a way to read this temperature?
What's it called?

[moorgate]

test drive all good. Some smoke left over, though i think that's crap being cleared out now the IC flows properly and the quantity of air is measured correctly. Nothing like the volumes it would put out before...

A little slower to come up to temperature, because I got the oil gack off the bottom of the water radiator - but that's hardly cause for compliant. Altogether, going fairly slowly and with this being my first time on this job, I spent about 5 hours over 2 days, not including the various cleaning phases on the fan shroud, under-cover and radiator.

Oh and if any of our Breaker fraternity have an engine undertray for a 2003 V70 D5, I'm ready to talk!