Oil Cooler Change

Evening, about a week ago I had planned to take the car somewhere and decided to check the fluid levels before going and found coolant to be low and signs of mayo in the header tank. Having had a few issues with the car lately I had the hump but decided to pm Iain (demort) as he's best placed to offer an opinion on my latest issue.

Iain's thoughts are the oil cooler has failed as there is only a small amount of oil in the coolant and the oil is completely clean. I read around online and found everyone describing the job as very difficult to do with the engine in situ. Friday night the wife had to work late so I decided to have a look at the job and emailed Iain some pictures of my findings and he suggested I make a post so others can see what's involved and share my opinions on the job.

Below are a series of photo's I took during the job





that's what I discovered after topping the coolant up and leaving it a short while, there's very little oil in there but enough that it's discolored the fresh pink coolant already.







managed to snap the final bolt for the plastic upper manifold on the drivers side as you can see there's plenty of it left to work on I'm sure a few days soaked in plusgas and 2 nuts locked together will remove it. You can also see the oil cooler clearly.











Iain assures me the amount of oil in the various components above is a normal amount, I decided to remove the left hand upper plastic manifold too as I already had the alternator out to replace the regulator.







the above is a vacuum operated inlet changeover valve, the valve feels fairly seized up and is supposed to be connected to the stub in the bottom picture and isn't so someones been in here before me.





turns out it is the original '97 oil cooler still fitted, and the new one by the same manufacturer but not from an opc.

Now regards the job itself everything I read described it as a horror story but in truth all of the above took me about 2 hours including dodging the rain, a quick run down of the job goes

disconnect battery earth terminal
release aux belt tensioner and slip off belt
remove 3 bolts securing a/c compressor (rear bolt is awkward but you can get a socket and extension between the runners on the plastic manifold pull out and position near engine mount)
remove alternator (2 bolts plus wiring)
use a syringe and hose to remove fluid from power steering reservoir, remove reservoir (1 bolt, 1 quarter turn connection)
remove throttle body (4 bolts, unhook cable)
disconnect o2 sensor wiring
use trolley jack to support engine remove bottom nut off both engine mounts then lower engine with jack until you can get your hands to the rear jubilee clips
loosen jubilee clips holding crossover pipes between manifolds.
remove drivers side upper plastic manifold (6 bolts)
remove centre crossover pipes
remove passenger upper plastic manifold

all of the above requires very little in the way of tools or mechanical prowess, below is a picture of the tools I used except for the jack and a 1/2" extension bar and a 15mm socket



that's a £10 halfords 1/4" socket set, a 1/2" ratchet with 18mm socket, a 24mm socket and a pair of waterpump pliers so probably £35 worth of tools, so there's no reason why anyone couldn't do this job i'm now just waiting on some new o rings for the oil cooler and i'll get the new one fitted and see where we are

Chris

Excellent write up young man , thank you , fingers crossed it fixes the fault .. dont forget rag / paper in the coolant bottle to remove as much of the oil as possible

Received an email from d911 today saying my seals and bits will be with me tomorrow so I thought I best remove the old cooler and that broken stud ready for the new bits or so I thought.



that's 8 litres or so of coolant drained from the hose that joins onto the water pump so pretty much what's in the engine and header tank.



old oil cooler off and that's the old o rings above, the rear most big o ring seems to have suffered some corrosion that's eaten into the engine surface really not ideal but hopefully most of it will clean away with a stanley blade and a bit of instant gasket should seal it.

I then decided to look at the broken stud which promptly decided to snap flush with the hole so now ill be removing the piece it's in to drill it out which leads to my next question, is there an easy way to disconnect the fuel feed (drivers side) without removing the injectors as I haven't ordered new injector seals

chris

First off .. thats a lot more oil in the coolant than what i thought .. still .. replace the cooler and we will see .

I think some sort of flush might be in order .. that amount of oil will coat every pipe and take monthes of use to work its way back to the resevoir , mind you a cold flush wont really remove it , any kind of solvent could damage the pipes .

Dont really have an answer here im afraid ... Porsche just stipulate replace the rubber pipes !!

Second .. off hand im not sure but ive reused injector seals in the past with no problem .. actually quite a few times .. its rare for them to get damaged and they are pretty fat so tend to be fine .

There's not as much oil as you'd think it looks worse in the pictures, I think it took 5 paper towels to skim the majority off the top.

I've already thought about flushing the pipes and to that effect I've ordered 25l of deionised water and speaking to some other people I know who know all about oil in water (mgf owners) they recommend hose the system out as best you can then a couple of bottles of forte bio degreaser in with the deionised water run it upto temperature then dump the lot and hose it all out again.

Do you normally remove the injectors from the manifold there in or just remove the clip holding the fuel rail at the top and lift the rail off there?

I would undo the rail bolts then try and lift it at each end .. with luck the injectors will come out with the rail .

Just do it how you feel comfortable .. if you prefer to unclip the injectors from the rail then do it that way .

I remember the forte degreaser now .. ive used it pre Porsche .. but to be honest forte fuel conditioner worked better but best not to use that on a Porsche .. it will probably be fine but when i last asked 10 years ago they couldnt be certain .

I ended up removing them from both the rail and the manifold in the end, with the manifold out I managed to drill a hole in the snapped stud and once I got it drilled out enough could remove the remains with a torx bit hammered into the hole and some heat so that's sorted.

I then refitted the injector manifold and cleaned up the mating faces for the oil cooler and removed the old o rings so i'm now ready to refit the new oil cooler.

No pictures as my laptops playing silly buggers but it's all back together, idles better now I've reinstated the intake crossover valve and reconnected the vacuum lines the way they should be.

Spent 4 hours draining and hosing out all the coolant pipes and radiators until they all ran clear, this was after adding 2 bottles of forte degreaser to the system, the coolant came out like coffee. I've refilled it with deionised water managed to get about 13 litres in so far and having ran it at idle for awhile there's small amounts of oil settling in the coolant tank which I'll periodically remove with kitchen towel over the next few days and once it finally looks to be staying clear I'll dump all the deionised water flush the system again and refill with antifreeze and hopefully that'll be the end of it.

Next is to sort out why my dash is lit up like a Xmas tree and the batteries not charging, I swapped the voltage regulator out for a new one whilst I had the alternator out sometimes it starts and charges properly other times it doesn't think my first port of call will be the main earth strap between the engine and chassis it looks like it's seen better days

Ive seen other people swop the regulators out on the forums here and it causes a problem so it may well be that .

Engine earth lead is more for the starter .. that has a huge current draw so needs a very good earth ...

Always possible but my feeling is its alternator related.

Reguards the coolant .. with that amount of flushing it should be pretty clear .. if its black spots of oil you are seeing then thats not a good sign .

You need to run it a bit and see what you are getting in the tank .. ill be happy when you say its clear but atm im a little dubious

Sorry to be a pessimist .. but its what i do .

Thanks Iain, if the pessimist in you is right then what are your thoughts on what's putting the oil there?

Removed earth strap this evening, it's seen better days so I'll make a new one. I'll see about getting another alternator then.

Cracked head im afraid as per the first emails .. no way to find out which one unless you strip each one in turn , you need to look under the tappet carrier (under the camshafts ) and at the core plugs , there will be a line / crack from one of them .

Normally you get some coolant in the oil but not always or not enough to be noticed .

Oil cooler is the cheap option as they do fail .. cracked head isnt a cheap option hence we replace the cooler first and see from there.

Head gasket failure is pretty rare and you tend to end up with D chunk if its that .. cylinder lineing broken appart .

Small black spots of oil in the tank kinda indicates its fresh .. thats why im concerned.

It may be nothing , it may be old residue .. but i would like you to run it for a while and see if you keep getting more black spots of oil .

Nothing that's in the coolant tank currently looks like fresh oil but until I get this charging issue sorted I can't give it a proper run out to test

Ok im feeling a bit happier about the oil now :thumb:

One thing i hate doing on here is giveing bad news , i have to do it at work sometimes and its not pleasent but its best if i say what i think from whats posted .

Reguards the alternator , i take it there was no problem before you worked on the car so the voltage reg seems the most obvious ..

At the end of the day there is only a single blue wire going to the alternator and thats the feed via the instrument cluster bulb .

A question though .. what do you mean by all the lights on ? duff alternator and you just get no charge , sometimes with the light on but not every light ?

Ok, alternator first. on a few odd occasions over about 3 months when having started the car the traction control light, abs light and battery light would all stay on and the voltmeter would show the car not charging (confirmed via obd readings) restarting the car normally cleared them and it would charge properly.

The same week I noticed the oil cooler issue the lights started staying on permanently, I googled it and the voltage regulator or brushes were stated as the probable cause so I replaced them whilst doing the oil cooler job. Fast forward to today and I took the car out for a drive (fully charged battery) covered about 20 miles and bizzarely noticed if I keep the revs above 4k then the lights go out but the car still isn't charging so the issue probably is the alternator still I've another one on the way Monday.

With regards to the oil situation as I said above I took it out this afternoon, left it to cool down and I've just checked the coolant tank, I've had to top it up with 2 litres of deionised water but that's not unusual considering I've had the system virtually empty, all that's floating in the water currently is some very white oil residue, so far no sign of dark fresh oil but the 20 miles I've done albeit at a fast pace aren't really conclusive

The oil is looking good .. a continued leak would cause small black spots of oil in the tank .. you dont seem to have this so you may just have cracked it forgive the pun !

Alternator .. ok im with you , replace and see how you go .. if no luck , which i doubt , then ill dig out some diagrams and have a ponder .