Oil cooler trouble

[iang]

Help..................!

Just got my S4 out of the garage, found a big puddle of oil under the left hand front wheel.

Taken a look, and I think my oil cooler is shot.

Called in at Paul Matty's garage.

[oneshot]

Topic moved to technical section.

[andydclements]

Be ready to get covered in oil- have some vinyl gloves and cable ties ready (not latex gloves) to ppop over the tube ends and close them.

[Daniel]

I had the same with my S4

PNM supplied and fitted new for not even close to that figure.

They also did the dreaded manifold at the same time and the bill for the lot, including parts was less than

[Tentenths]

Pretty sure several owners have sourced broadly compatible coolers from Merlin Motorsports

[fjmuurling]

I think SJSportscars have the right oilcooler for an S4 at 149 pounds ex VAT.

[Malc Holmes]

I fitted an SJ replacement on mine when it started leaking. The replacement cooler was identical to the origonal. Problem is getting the couplings off the old cooler. They tend to corode them selves on the the cooler and I could just not get them off. In the end I got replacement couplings made up, cut the hose itself, extended the hose to the new couplings. Job done, for about

[internets]

I had to replace an oil cooler about a year ago, and like most cars the bottom connection was totally corroded. I decided to cut the through the oil cooler just above the connection and then very carefully, using a dremel, cut out as much of the aluminium as I could then I re tapped it.

I remember recently reading on the forum someone used acid to dissolve the aluminium which worked very well for them.

Again I brought one of SJ's coolers @

[fjmuurling]

Hello,

I dissolved a piece of aluminium 2 days ago in one of the couplings with a Sodium Hydroxide solution (NaOH). This only eats the aluminium and not the steel coupling or hose. Do not use acid, this will also "eat " the coupling.

Freek.

[iang]

Thanks to all for the information.

I have just placed the order for a new oil cooler from SJ's.

Now I have to start getting the old one off..............

I can say I am NOT looking forward to this one...............!

See you some time in 2014

Once again, thanks.

[Andjons]

Daniel - I now own your old S4. I take it you were aware that the right-hand cooler was removed and not replaced?! I am currently a uni-cooler.

[Daniel]

Daniel - I now own your old S4. I take it you were aware that the right-hand cooler was removed and not replaced?! I am currently a uni-cooler.

From what I recall, the problem presented itself the day I collected the car from storage to take it to PNM for the new manifold.

There was an oil leak to one side, and obviously PNM diagnosed it as a leaking cooler/hose connector.

I remember discussing the replacement of both units, and I thought that's what had happened..............BUT

I do remember Richard (the guy who had the car off me as a trade in for my 350) telling me it only had one cooler, but I gave the issue little credibility as....well, frankly I'm of the opinion that he's an imbecile.

So......doubtless it has one cooler.......how it ended up with one cooler, I have no idea.

[Andjons]

Not that it matters really - unless we have a heat wave and I get stuck in London traffic! Hope the 350 is doing you well.

Edited March 7, 2009 by Andjons

[glynherron]

Guys I'm having the same problem with my right hand cooler

The lower coupling sheared in the rubber hose....

I like the idea of disolving the aluminium rather than dremmeling and retapping due to swarf ingress etc.

So, how concentrated a solution do I use?

Freek, could you or someone else tell me how much water to how much weight of sodium hydroxide to use?

I'm still struggling to get the upper locking nut from the cooler. Looks like i'm going to have to grind through the nut, unless someone has another idea for me to try.....

Thanks guys

Glyn

Edited March 23, 2009 by glynherron

[fjmuurling]

Hi Glyn,

I don't know what concentration I used. I just filled a glass jar with hot water and let the affected coupling hanging in the water. Make sure the thing is oil/grease free otherwise it is not going to work or very slow. Once the coupling is in the jar with the water i just put some (a fair amount) of the NaOH beads in afterwards I just stirred (not shaken) until everything of the NaOH is dissolved. You can tell that the NAOH solution is working when you see the forming of very small bubbles. Maybe you have to renew the solution a couple of times. It can take some time.

I did it on an evening but when everything was in place I had to work and I just left it and thought well I have a look when I come back which I forgot, I chekced everything aprox 24 hrs later and voila the aluminium was gone.

DO USE GLOVES AND A EYEPROTECTION JUST IN CASE.

Let me know how it goes.

As for the upper nut (do you mean the 28 mm thin nut) I ended up of cutting it through with my trusted dremel with the flex shaft.

Freek

[glynherron]

Freek, thanks for the info

Yes the 28mm thin nut!!

Will get hold of some sodium hydroxide and see how it goes. Just hope I dont add too much and shatter the glass with the heat produced. Can I use a tin, or will it react with the solution??

Oil coolers out of stock at SJ but I guess I'll just connect the pipes until they are available

Thanks again

Glyn

[fjmuurling]

Hi Glyn,

use a glass jar, a tin is probably galvanized and will be eaten by the NaOH solution. Glass is heatresistant and the solution will not boil (I didn't experience it).

Freek

[glynherron]

**** Update ****

Well the sodium hydroxide worked a treat

While the oil cooler is on order (5 weeks delivery from SJ) does any one know the thread size so I can buy a male/male union to connect the flexible pipes together (for now)?

Thanks

Glyn

[Advantage]

5/8" BSP

[glynherron]

Wow thats fast !!

Thanks - hopefully be back on the road for the weekend - yippeeeee

Glyn

[Advantage]

Merlin Motorsport clicky

[glynherron]

Bought the 5/8 GSP male/male adaptor today....