Mark944na86

What would be the max oil temps you would would expect to see in a daily driver?

I had a strange gasket failure today, and I'm trying to figure out if the gasket sealant (Loctite #3) I used is the problem. I just looked up the data sheet and it says it should be good to ~200C (~400F). Bit of a long shot, but it has me scratching my head... the valve cover gasket was refitted with sealant a few weeks ago, and it had held without any apparent leaking, but suddenly, *lots* of leaking, and not just in one place.

The car was being driven moderately hard today, but not excessively so. The coolant temp was only showing a fraction above the first line on the gauge at max, so the engine never overheated, although it was running a bit hotter than it has otherwise over the last couple of weeks.

I used gasket sealant because I was reusing the old gasket, rather than replacing with a new one. Seemed like a good idea at the time...

Bri Bro

The reuse of the gasket might be the problem. After the gasket gets oil in it, it is hard for sealants to bond to it. What can happen is the sealant acts as a slippy surface for the gasket to slid on, cause gaps to form. Oil temps will lag behind water temps after startup. For normal driving, my oil temps run real close to the water temps. On the track, I have seen 260F which is a far cry from 200C.

APKhaos

There's something seriously wrong if street driving get oil temps above 220 or so. Hard racing on a hot day will push oil temps up to the 'shut it down' limit of 250F without a second external cooler.

The loctite is not failing. Prep is the most likely problem. If the surfaces are clean and dry the gaskets generally seal well. No extra sealant required.

Josh B

Hi Tony,

Where are you measuring oil temp? I've seen over 250F for the oil coming right out of the turbo at the banjo bolt.

Techno Duck

Don't think I have ever seen more than 210*f, that was sitting in traffic on a hot, humid NY summer day. That is taken at the drain plug with the stock cooler.

bearone

reusing the head gasket was a poor choice.

Josh B

Jon - you have to be experiencing oil temps of above 210F. the stock oil cooler thermostat doesn't even open up to the cooler until 105C or about 221F. Are you sure you are using the right sender?

Techno Duck

Yup, this is with my digital SPA Technique gauge. Even when I was using a VDO gauge I had the same results. On the track is a different story.

Josh B

Hmm - very envious of the SPA gauge

fbgh2o

I get about 205 to 210 max, idling in traffic. 160ish on the highway at cruise, IIRC

Eric_Oz_S2

When I reused my gasket after replacing the hall sensor, I did notice that there was some minor "leaking" (more like weeping). The cam cover bolts don't allow much compression of the gasket, and I think they may actually bottom out in the holes - my observation from the way they suddenly stop when tightening. My reused gasket was only 3 years old though. In installed a new gasket after later repainting the cover. FWIW I used permatex grey for the new gasket - but only in the corners (and over the "hump") as per the Porsche recommended procedure.

Mark944na86

Thanks for your comments everyone.

Eric -- where do you buy your permatex?

I had the cover off again today to check out what was going on, and it wasn't a simple leak -- there were actually some small chunks of gasket missing in two places. I hope they got blown out -- I couldn't locate the missing pieces, and I don't like the idea of them floating around under the cover. Weird though. How much pressure builds under the cover, I wonder?

Anyway, clearly time for new rubber parts for the cover -- I'll put an order into Pelican today to get a complete set of rubber parts. In the meantime, to attempt to keep the car on the road while I await my package, I've attempted a temporary repair, repairing the gasket with RTV gasket former (Silastic), and then reinstalling with Loctite #3 over the whole mating suface. I torqued it all back up (I listened to Eric and disconnected the fuel hoses from the fuel rail this time -- much easier) and am now waiting for for things to fully cure (24hrs) before testing. If it fails immediately, then I'm no worse off than I was this morning... but if I can a couple of weeks of use out of it before my parts arrive to do a proper job, I'll be happy.

Unfortunately, I think this rules out an AM session at QR tomorrow, Eric. The planets just didn't line up this time.

Thanks once again for your advice, everyone.

Eric_Oz_S2

Permatex Ultra Grey can be had from Supercheap Auto. Mark, I actually still have the old gasket - just had a look and it still looks new (not cracked or stiff). As I said it only weeped slightly, didn't actually "leak". You're welcome to it if you want. I could bring it with me to QR, if you're up for a quick change.

Mark944na86

That's very generous of you Eric -- thanks a lot. Actually, I'd even be nervous about the drive down to QR tomorrow morning (about 1 hr away from where I live), given the temporary fix wouldn't strictly have finished curing by then, and I'd really like *not* to get stranded somewhere on the Ipswich motorway between here and there.

However, if my temporary fix does fail in the interim, I'd certainly appreciate a loan of your old gasket as a Plan B. Once I've got my new part in, you could have it back (assuming you still want it -- and why not? Obviously still useful at a pinch.)

Techno Duck

For that gasket, I would personally use Hylomar. I am pretty sure Permatex is distributing it again so you should be able to find it at your auto store. It is a great gasket prep and is non hardening, so it does not make a mess on disassembly and will not clog oil channels if you use too much. It is oil, fuel and coolant resistant.