Cleaning the oil cooler

[neilbardsley]

I'm still not complete happy with the temp that my engine is running at. I'm thinking about doing a lazy exterior clean of the oil cooler. Using brake cleaner fluid, tooth brush and pressured air (so I don't have drop the engine)? Stupid idea or OK if I make sure I don't move the cooler and damage the seals?

[Nine One One]

Neil
I cleaned mine that way on the 912, most of it was full of dried sand, crusty stuff, like dried mud (ex So Cal car)
I found the air line cleaned it fine, started off at a distance with the air line, and as it got cleaner, moved the line further towards it.
I would resist against ‘poking’ anything through the gaps in the matrix just in case you do actually puncture something.
Another thing you can do is make sure the relief valves are not all gunned up, the springs OK and they move freely in the slots.
If the matrix is full of black and oily crud in the matrix, you may find it has a leak, and that crud is stopping it from weeping out everywhere?
Have you tried the old trick of holding the dipstick when the engine is fully warmed up to see how hot it gets………..thats the end of the dipstick with the hook, to pull it out of the sleeve. (old VW air-cooled test method)
I’ve always pulled it out and held the very end - whilst hot it is not too uncomfortable to hold (bit where the high and low markings are on it) just to make sure as well
If the dipstick is at a reasonable temperature either your sensor or gauge could be faulty?
Other things to check are the timing, fuel mixture, tappets…………..spark plug heat rating……...

They used to sell these in the UK at one time, not sure if there is a distributor over here for them?

http://vwparts.aircooled.net/Dipstick-O ... pstick.htm

this refers to VW air-cooled, but basics are the same

http://www.vw-resource.com/overheating.html
Ian

[neilbardsley]

Thank you for that.

It's been on going for a while

-> I have an infra temp gauge so I think that my in car gauge is roughly about 10F too higher but that could be the difference between case temp and oil temp?

-> I've been back to basics and worked my up from the setting the values, timing (although I did advance it a bit on the w/e so will move back), carbs but I think think that compared to my 912 this engine is running a little too hot. It does get too hot to the touch

- new plugs. I moved the heat rating higher from 6 to 7

-> The rpm gauge is reading low so I'm putting a little more stress on the engine than I think. 3k on my in car gauge is actually more like 4k

-> It has a newish Alu cooler but some sound proofing material which get pulled into the fan. However, on inspection I don't think the oil cooler was that dirty but I want to revisit.

-> The car is running nicer than ever. Nice torque through the entire rev range.

-> Reading the 356 registry they there is talk about ensuring that the flapper boxes are open (during the summer). Plus that I have a screen which is missing of some cars.

[Nine One One]

Neil
I take it the fan belt is the correct type i.e. a proper V belt and not the ribbed sort?

I don’t think the 912 has the flapper boxes? Not sure what year your engine is, or are you on about keeping the heat on in the car during the summer??

On the point of your infra read sensor, cheap ones are inaccurate, have you tried to measure a cup of boiling water after putting a thermometer in it to see its accuracy?

Have you tried the dipstick method, you say its hot, but not how you know its hot, the engine back is fairly enclosed so it will get hot in there especially when stationary and no air flowing under the car, or cool air coming in.

Are you sure non of your insulation got sucked into the fan, and its blocking any of the ducts inside? You’d be amazed at the amount of crap that accumulates in the fan housing as well, so if you are going to check the cooler and the fan housing is off check it all, and that your not missing any blades, and whilst you're there check the duct for the dynamo is in the correct position on the face plate that bolts onto the housing. Likewise clearance between the back of the fan housing and the fan itself, the gap should not be that big, can’t remember the exact spacing, but you should be able to see if its too big or not.

If it gets that hot you will know as it smells hot, you also see paint peeling on the tin ware.

There could be a number of issues as mentioned, but you need a decent temperature gauge of some description before you start chasing things that may not be there?
Ian

[Nine One One]

Whilst you are at it Neil, up the insurance on your 912 Targa…………seen this?

http://www.ebay.co.uk/itm/Porsche-912-T ... 464006cbb2

[neilbardsley]

Whilst you are at it Neil, up the insurance on your 912 Targa…………seen this?

http://www.ebay.co.uk/itm/Porsche-912-T ... 464006cbb2

That is not even a soft window!

Sent from my UP520 using Tapatalk

[neilbardsley]

Oil cooler cleaned but it was pretty clean already. The flapper boxes were completely open. Mike Smith has kindly directed to the panel that shields the oil pump from the exhaust so I will fit that. The think the only answer is now that the distributor is over advanced at higher rpm.

Does it makes sense that as the springs in a distributor become weaker, with age, it the distributor advance more then original specified?

[pauldvern]

Hi Neil

I had an advance problem with my distributor. The dowel pins that the weights fit on inside the advance mechanism had worn. They had a large groove in them so I filled in the groove with a weld and then filed them to a perfect round again. Advance returned to normal.



Paul

[Winston Teague]

Weak springs will allow the distributor to advance more quickly, though no further than it did before. Retarded ignition will cause the engine to run hotter, as will a weak mixture. The mixture is very important, changes over time (as does the recipe of petrol) and i would recommend a rolling road session asap. W

[mycar]

I'm still not complete happy with the temp that my engine is running at.

Evening Neil, just remind me why you're not happy with the engine temp, I've had a thought*.

* (an infrequent occurrence, we should try and make the most of it.)

[neilbardsley]

The in car temp gauge gets beyond 210 (mid point too) quickly. I've checked against an infra temp gauge and maybe the in car gauge is 10-20F too hot. The engine compared to my 912 hotter to the touch. I can drive pretty much all day in the 912 at 4k but not in the 356. This is an issue that my rpm gauge is off but even adjusting for that something is different.

I've been back to basics and checked the values, timing (which isn't stable enough for me), carbs and fan belt. All of which my be a sum of small errors from me! Next I'm going to check my temp send in a cup of boiling water and look at the distributor.

The car is however running very nicely!

[mycar]

Aha ! Your thoughts are like my thoughts, I too was thinking temperature sender.

I was thinking that the engine may be fine but the oil temp sender may need calibrating to you temp guage, be the incorrect sender or just be knackered.

Have you considered fitting a VDO dipstick oil temp sender ?

http://www.machine7.com/product.php?xProd=3261

[neilbardsley]

Then I get involved in temp in the slump v the top of the engine. I generally see the slump 20F plus over the top of the engine so that would just panic me more! I think I would like to know that the current setup is displaying the correct temp first.

As an aside if I understand correctly temp at the head is where most of the heat is? From my www reading some of the serious racing boys install temp gauges in the heads.

[vwgillybilly]

I think comparing engines is where you're eating yourself alive.

There are lots of other variables which could lead to higher temps in the 356 motor such as oil type & compression ratios which even though set the same initially will change with wear.

How reliable is your I.R temp gauge?

[neilbardsley]

I think comparing engines is where you're eating yourself alive.

There are lots of other variables which could lead to higher temps in the 356 motor such as oil type & compression ratios which even though set the same initially will change with wear.

How reliable is your I.R temp gauge?

Good points however

-> Same oil VR1 Racing

-> My 356 motor is a Pellow industrial engine and I think he was quite conservative on his compression ratios. That said I've no idea what ratio my 912 is using but I think the 356 engine is running too hot. The temp isssue has got worst since I've owned it. I do think that fact that the last person that serviced it before me was Jack Staggs implies that my tuning skills are suspect. However, it did have the wrong fan belt on it. I'm pretty sure that the rpm counter is reading low. Plus I suspect it was used for US highway driving where 55/65 is the normal speed limit so perhaps I'm pushing the car a bit harder than previously. It's not an obvious problem as the car runs very well. I'm going to change the oil on Sat. Tune again. Then hopefully some of Mike's 356 knowledge will rub off on me as he has agreed to sell me a part which deflects exhaust heat from the oil pump.

-> I'm not sure that my IR temp gauge is completely good but I can check that too.