The big 2.3E coolant temperature mystery

[K Simmonds]

I'd certainly want a seperate radiator and oil cooler, I'm not a fan of the combined ones.

Someone posted a link to the correct size and proper quailty Behr rad fairly recently on eBay and it wasn't too expensive. The Nissens ones are pretty crap in comparison.

[Luuk813]

Hi newsh, thanks for the offer, but it's indeed not gonna fit since it's a 5 cylinder. I'm still hopeful that I'll find one some day, but for now I will see what the results are with my current rad after replacing the head gasket. Perhaps I might find a shop that is able to refurbish it even?

Speaking off, I finally got to remove the 3 bolts holding the exhaust manifold to the downpipe. I ended up removing the battery and used the hole in the battery shelf to get my arm and a retched underneath the exhaust, while my friend watched from below to guide me onto the bolt. I tried for ages getting the started off for more access, but it seems like the old owner used the wrong bolt getting it on, and rounded it in the progress. It should be an M12, but it is now an rounded M10! I'll try getting it of once I got the head removed, so that I have better access.

The engine bay is ready to remove the head, but I'm a bit hesitant on removing the timing gears, since I'm not certain where to find the crankshaft timing mark. The camshaft timing mark is really well marked and clear:
PXL_20230903_110232091.jpg
I can't however find the crankshaft one. The Audi manual shows this image to check the timing at the flywheel (automatic transmission) but there's no mark on the flywheel housing on mine. I'm also not certain what to align it with if it was there. I assume you align the notch next to the 0 with something, but the second photo shows the place that line is when I put the camshaft on the timing mark. Is the timing already not right? This kinda stuff doesn't seem like something to be confused about or to figure out later, so does anyone here have any experience in timing an 5 cylinder with an automatic gearbox?
Screenshot 2023-09-03 181437.png PXL_20230903_105608061.jpg

[Tractor Dave]

Remove spark plug on cylinder 1 and using a long screwdriver, establish tdc by using a ratchet on the vibration damper and rocking back and forth. You will find that the 0 on the flywheel will be just under the bell housing window edge.

[K Simmonds]

Remove spark plug on cylinder 1 and using a long screwdriver, establish tdc by using a ratchet on the vibration damper and rocking back and forth. You will find that the 0 on the flywheel will be just under the bell housing window edge.

Yeah, this is what I do it saves time and is more reliable than the crank marking which is a dimple in the metal on the lower timing belt cover that is supposed to line up with a small cut/knotch on the inside wheel of the vibration damper all of which has to be removed to change the belt so isn't much help once it's appart. The is also a mark on the flywheel but this can be very difficult to see.

Have you got a way of locking the crank and undoing the centre bolt sorted?

[Luuk813]

Thank you for the tip Tractor Dave ! I'll give it a try next week, once I will have found some time to continue.

I did get the centre bolt of already K Simmonds, but I didn't lock the crank however. I used an air impact wrench, so that the crankshaft didn't turn (well, only very very slightly) when trying to remove the bolt. I didn't fully remove it yet, since I wanted to do that once I got the timing situation figured out.

For installing / torquing it correctly I'll try to ring op some local garages to ask if they have Audi tool 2084 for me to lent. I guess that I will have to try to make one myself if they don't have one. I figure it will take quite some time to get the head skimmed & tested, so I will use that time to collect tools/do some planning on getting it all back together. For now I'm mostly worried about the disassembly, and very curios about what state my headgasket is in

[Tractor Dave]

Impact wrench, crank bolt

[Tractor Dave]

But seriously, it's well known to crack the locking key.

[Luuk813]

Excuse my ignorance Tractor Dave , but that wasn't known to me at all. You got to remember that this is my first time working on cars in this depth. My friend recommended me using one when I mentioned that I didn't have a tool to lock the crank, and I thought it would be fine to use for the disassembly at least. You got me a bit worried now I must say.

So far I haven't noticed anything out of the ordinary, guess I'll see when I remove the pully?

I think this can be seen as an honest mistake, and something to learn from. I just hope that it's not too expensive of a lesson / that I didn't ******ed anything

[Tractor Dave]

We all started the same way and made plenty of mistakes. Don't worry. I would recommend changing the bottom pulley now. A hairline crack may not be obvious but could well cause catastrophic failure and terminal engine damage. Most of us here change that pulley anyway.

[Luuk813]

Well, I've managed to remove the head yesterday after not noticing there was a fourth exhaust flange bolt that helt the head on for hours

It's pretty clear that there's an issue, since there's water/coolant in cylinder 3 & 5:

PXL_20230905_154758160[1].jpg PXL_20230905_154709883.jpg

Alot of the water jackets got blocked/gunked up aswell, but I think that's just the headgaskets design.

Next step is going to be letting the head skimmed & pressure tested, cleaning up everything, and replacing as much wear items as possible now that I'm in there.

Thanks for your guys help so far

[Tractor Dave]

That's very gunked up. If all you hoses are like that I think you just discovered why it's overheating. This will in turn have caused the head gasket to fail.

[Luuk813]

It's most likely a good idea to clean out the entire system with something like a coolant flush then, once I get it back together. I most defenitly want to do that before replacing the radiators, before the new ones get gunked up aswell

[Luuk813]

Well, it was finally time for me to continue working on the Cabriolet. So far I've got the head skimmed and valve stem seals replaced, and I'm now working on putting the head back together.

Today I started cleaning the head gasket surface on the engine block. I used a scraper knife & some green scoth brite to remove the layers of gunk and left over head gasket material. After working on it for 2+ hours, I can't seem to remove the imperfections around my water jackets:

PXL_20231007_115658283.jpg

When I run my nail on it I can feel the surface imperfections a bit, but it's very slight. The water jackets and the (corrosion) imperfections run pretty close to the cylinders, which you can see by zooming in on the picture above. Is this something I should be worried about before putting the head on again, or is this to be expected?

Furthermore, does anyone have any tips of cleaning out the oil channels?

[K Simmonds]

Clean the top of the block with course sand paper on a flat block until you get a semi shiny surface. Try and use good quality stuff that doesn't shed too much sand and dust, I find 80 grit 6" sanding discs perfect for the job. The oil ways will clean themselves on the first start. I always use cheap 10W-40 for the first start let it run up to operation temperature, then drop that out to get rid of any debris in the sump. Then use a better quality 10W-40 for an 7A/NG motor along with a fresh filter.

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[K Simmonds]

Just had a good look at your photos, you've done a pretty good job of cleaning the deck though I would go over it again as I described.

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