Cracked Head

Thankfully it was a cracked head on my 99 996 C4 Cab - awaiting to be repaired by an independent and then reasembled by the dealer, who advised that I need a new clutch and flywheel - which may or may not be the case. If there are any out there, please let me know. Now I wish I had purchased an after market warrenty. Thanks

Warranties don't cover wearable items like a clutch, brakes, tires and so on. Where did the head crack? Also, ask the dealer, what is the measurement on the clutch disk and why do they think the flywheel needs changing?

JWP - I, for one, like your attitude. Get in, fix it and move on. It's a car - just a car; you'll be back behind the tach in no time.

Watch for collateral damage! Did you have intermix symptoms?

What should one look for as far as collateral damage after an intermix? What signs would suggest unsalvagable status?

Oil in the coolant tank is one visible way to identify and intermix problem.

When I had my cracked head and intermix back in 2008 I had extensive intermix. The coolant was literally the consistency of thin pudding and the oil was like a chocolate shake. I think I was among the first on this bard to do a DIY fix of this problem. As I did not find the problem until the coolant light started flashing when my wife was driving the car I assume it was driven for a while with contaminated oil. I am sure that this was good for the bearings, if you read on the subject of contaminated oil they say even a small amount of coolant in the oil can cause damage, and I had way more than a small amount. However I could not afford a new/reman engine, did not have the tools, etc. to split the cases and replace the bearings, etc., and was not sure the fix of the head would work. So I just had the head repaired and did some other related work. I don't know if my engine will go to 200,000 miles on the bearings but I can tell you that I have 18,000 miles since the fix and the car is running strong. So $500 to repair the head and get a valve job on that side, another $500-$700 in parts directly related to the repair ( I did other work when I had the engine out ) and about 40 hours of learn as you go time and I am pretty darn happy! By the way I have a brand new, in the box, 1-3 head for a 3.4 VarioCam engine sitting in my home shop. It includes the head with all the valves, springs, etc. and the cam cover. You use your own/old lifter body, lifters, cams, advance mechanism, chains, scavenger pump, etc. the list price is $3,152.10. I want $1,400, figure about $50 for shipping. Just throwing it out there. If I don't sell it I will keep it "just in case".

Yes, it was an intermix problem. Head is cracked on bank 2. I will followup with the dealer early next week prior to the reassemble to check on the clutch/flywheel issue. Doug.... I sent you a personal email rougly two weeks ago and heard nothing from you - I thought you may have been vacationings. So you sent approximately 2 grand for the head work? It looks like I'll be spending that much or more on the diagnosis and reassembling.

JWP I was on vacation, riding our Harleys in Colorado. Still trying to catch up with work, etc. I will check my emails and try to get back to you.

That's a really good price for a new head. I was quoted $4000+ when I needed to replace a head on my 3.6. OP, who is doing the work?

Just in case anyone is keeping a tally.... chalk up another intermix situation attributable to cracked head around #1.

Well thank goodness they never crack in any of these spots:

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Carry out a compression and leak down test.. We see a huge portion of intermix cars with cylinder issues from the intermixed oil that has no boundary layer protection. Over 1/2 the cars that we could save have been compromised by being driven to death. We also see accelerated rod bearing wear from intermix engines. Lots can be told by pulling the sump and cutting the filter open. I see two cracks in that head. Both are repairable with our regimen. But definitely ensure the remainder of the engine is not compromised.

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Do you have pictures of what it looks like in the pan and oil filter ?

Where do you guys send off the heads to be fixed? What exactly is the fix? thanks, Mike

So if you don't visibly see oil in the coolant or coolant in the oil, what is a good way to monitor for intermix? Oil analysis every time you change your oil? I'm not anxious about it or anything but wouldn't want to drive it to death if it ever does happen.

I sent my head to Costa Mesa R&D/John Edwards. This was back in late 2008 early 2009. Not many shops were doing the fix back then. Back then when I called John as soom as I told him I had a crack and before I told him which headend where, he told me exactly where it would be (inner exhaust spewing seat on cylinder 1). I think this is the most common crack. There is another shop in Athens GA that is advertising in Excellence magazine that it fixes cracked 996 heads. I am sure that Flat 6 has a shop if they don't do them in house.

Not to push it too hard, but if the price of the crack repair has increased (I heard one quote of $800 recently) and you need valve work, etc. in addition to the crack repair, the $1,400 I want for the new head I have is not too bad of a deal.

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Roger. Sleeves visibly look ok so far -- no cracks, no d chunks, no scoring, etc. Will plan to ensure longevity with recommended testing. View from the bottom below. Oil had been drained when I picked this motor up (bought locally off eBay, rolling the dice I know) -- filter was MIA as well. Guy I bought if from mentioned no coolant in oil and no shavings in filter. No signs of intermix when I dropped the pan. HELLA SLUDGE, but no signs of coolant or metal fragments whatsoever.

Where do you see the sludge? Looks clean to me.

In my opinion most of these cracks can be avoided altogether if 996 owners would adhere to 5 simple preventatives: 1.Change your Water pump long before it shows signs of failure (especially if your car still has the orignal WP - regardless of year or mileage! - These cars are at least 7 years old now) 2. Invest in the lower temp (160) stat - I don't want to get into an argument of whether it keeps temps lower or not - it does - no need to discuss. 3.Ensure the quality of your coolant and make certain you have the right mix for your region/driving conditions. 4. Make sure all hoses are in decent shape 5. Keep your radiators clean and ensure that all fans are working in both stages. and then drive the Sh*t out of the car.

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All that *might* help but it looks to me like they had a problem on the machine tool that does the finish size on the hold for the valve guide, resulting in a stress crack rooted in the base of the valve seat. BTW, that's my head with the red crack detector all over it in the other Doug's post.

Ahh' Doug, you caught me

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It's all good - we went through that miserable experience together, separately!