Cylinder head gasket | FerrariChat

Cylinder head gasket

Discussion in '365 GT4 2+2/400/412' started by Ewan, Jan 11, 2019.

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  1. Ewan

    Ewan Karting

    Jul 5, 2015
    222
    Dorset, UK
    While there is very little evidence of emulsion/scum on inside of the engine oil cap on my car, there is quite a lot on the inside of the radiator cap. To the best of my knowledge (and extensive car history file paperwork), the engine in my car has never been out and the CYG has never been changed. Obviously this is quite a big and expensive job (I’ll be paying an independent Ferrari specialist to do it).

    Questions - does it sound like I have to do it now, and if so, what else is sensible (within reason) to do at the same time?
     
  2. wda24729

    wda24729 Formula 3

    Sep 22, 2014
    1,000
    Devon, UK
    Full Name:
    Graham
    #2 wda24729, Jan 11, 2019
    Last edited: Jan 11, 2019
    Hi Ewan, it might be worth just checking / replacing the O-rings in the oil filter housing first. These two small rings provide a seal between the oil route and water route in the centre of the block where they cross.

    There's a thread on here somewhere, but I'm rubbish with the search function!
     
  3. Temerian

    Temerian Formula Junior
    Silver Subscribed

    Jun 17, 2014
    432
    Manhattan
    Full Name:
    Rick Temerian
    Hi Ewan, what is the mileage on the car? I had the same issue and when I started to go through the engine the timing sprockets were completely worn as were the tensioner pads. My car has a little less than 100,000 K but likely never had the timing chain adjusted. For me it was worth pulling the engine and doing the timing chain work as well as valves, valve guides and pistons and rings. Mostly for peace of mind but also because I have very little knowledge of how the car was treated in the first 36 years of its' life. I also have been doing the brakes, bushings, shocks and engine bay while the motor work is being done. I'll try to post some photos soon. Good luck with the project!
     
  4. wrxmike

    wrxmike Moderator
    Moderator Owner

    Mar 20, 2004
    7,573
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    Mike
    https://www.ferrarichat.com/forum/threads/oil-in-coolant.376670/#post-141621921
     
  5. Newman

    Newman F1 World Champ
    Consultant Owner Professional Ferrari Technician

    Dec 26, 2001
    14,092
    Canada
    Full Name:
    Newman
    Auto or stick? If its auto the oil cooler in the rad could be contributing to oil in the coolant.
     
  6. Il Tifoso

    Il Tifoso Formula 3
    Owner Silver Subscribed

    Oct 22, 2013
    1,546
    SF Bay Area, CA
    Full Name:
    Ruben
    +1 to start with the O rings in the oil filter housing... this is easy and cheap, compared to a cylinder head gasket.

    Ruben
     
    wrxmike likes this.
  7. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    33,736
    Austin TX
    Full Name:
    Brian Crall
    Almost never caused by a cylinder head gasket. Paul is correct. It can also be traced to the water pump on some of the engines. I cannot recall the architecture of the 365 water pump from memory.
     
  8. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    33,736
    Austin TX
    Full Name:
    Brian Crall
    Actually I had to look it up the 400i had a stand alone trans cooler, radiator just cooled water, not sure about earlier models and the 365 used the radiator for cooling engine oil like the C4.

    I stand by earlier statement, the last place I'd consider was the head gaskets assuming a correctly assembled engine. 365 and up had very few head gasket issues except for the occasional external coolant seep.
     
  9. Ewan

    Ewan Karting

    Jul 5, 2015
    222
    Dorset, UK
    My car is an auto, from 1979, so one of early 400i autos. Mileage is 57,000.

    Certainly, checking/changing the O rings would be a no brainer. But given the CHG is now 40 years old, I’d be surprised if that was still shipshape.
     
  10. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    33,736
    Austin TX
    Full Name:
    Brian Crall

    Is CHG supposed to mean head gasket? Why not? And with logic like that I can make a case for a complete restoration.
     
  11. raemin

    raemin Formula 3

    Jan 16, 2007
    1,825
    Lyon (FR)
    Full Name:
    R. Emin
    Changing the cylinder head gasket is not without risks: the head is often "glued" on the engine block, they are somes protrusions on the head that ease the removal, but it is easy to break the head in the process, so the safest procedure is to use a dedicated head removal tool. apart from the tooling, parts are numerous (valves, guides, joints, rings, ...). All in all that's not a worry free maintenance job.

    As a side note: already seen 6 engines wide open, not a single one with failed or damaged gasket.
     
  12. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    33,736
    Austin TX
    Full Name:
    Brian Crall

    365's just did not have head gasket problems. That said the OE supplier gaskets are now junk and another choice needs to be made.
     
  13. wrxmike

    wrxmike Moderator
    Moderator Owner

    Mar 20, 2004
    7,573
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    Mike
    Compression test and coolant test for combustion gases and examining the spark plugs will let you know if you have a head gasket failure.
    As Brian said, ( and he would know) these engines don't have a reputation for cylinder head gasket failures, so don't assume they are the problem simply because the heads have not been off in 40 years.
     
  14. Ewan

    Ewan Karting

    Jul 5, 2015
    222
    Dorset, UK
    The two Ferrari mechanics (from different garages) that I have chatted to have both diagnosed the problem as being highly likely to have been caused by a failure of the gasket. So I think I’ve resigned myself to going ahead with this job, and possibly skimming the head (if required) at the same time. Naturally the O rings will be replaced also. Well also look at the valves and guides, though I really don’t want the job to escalate out of hand.

    The heater has also failed - the fans blow nicely, but the air coming out is not hot. So they’ll look at that while the car is in. Hopefully just a blockage in a pipe somewhere.

    Once this is all sorted, hopefully within a few weeks, the car is then booked in with the body shop for a full glass-out, bare metal strip down and full repaint, then fitted back with some new glass, rubbers, badges, etc. So, the next few months are going to be expensive for me.

    Still haven’t decided on the final colour either. It was originally ordered in Blu Ribot, but before it went into build the order was changed to Bruno Acajuo, so that’s the colour it was actually built. But after about 6 years, the owner got bored and had the local Ferrari dealer change it to Blu Sera, which is the paint still on it now. Decisions, decisions...
     
  15. Bill26

    Bill26 Formula Junior

    Jun 19, 2005
    255
    Australia
    Full Name:
    Bill Murdoch
    Ewan, without trying to be, in any way, antagonistic, I question the wisdom of launching into replacing the head gaskets.
    Has either of the mechanics actually seen the car/problem? Has either offered their reasons for their diagnosis?

    Replacing the oil filter plate ‘o’ rings is a relatively simple/cheap job to fix a known issue. Certainly worth considering. I really recommend that you read WRX Mike’s write up on this.

    Replacing the head gaskets is an engine out job with all of the associated likely ‘while you’re at it’ jobs. For a start, there is a good chance one or both heads will be stuck on the head studs and just removing them can be a major difficulty.

    Almost certainly, the valve guides will be shot and if the engine has never been apart, not replacing the sodium filled exhaust valves is beyond contemplation. Then there are all the other issues that will certainly present themselves. Once the job starts, you are committed to the expense (and the time).

    If the ‘o’ring replacement doesn’t fix the problem and you don’t want to commit to an engine rebuild at this time, why not just put up with the issue until you are ready? Oil in the water won’t do any real harm (unlike water in the oil).

    Good luck whatever you decide to do.

    WM
     
  16. Ewan

    Ewan Karting

    Jul 5, 2015
    222
    Dorset, UK
    Both mechanics have inspected the car, and were concerned about the amount of emulsion appearing in the coolant - even immediately after an empty and flush through. I think that was their main reason for recommending the work. And that both have had to do this job many times on this era of V12 Ferrari engine, including on 365/400/412 models.

    On the one hand, I don’t want to open a can of worms. On the other, I want the engine to run well, and for the coolant to be clear and efficient. Tricky decision right now.
     
  17. raemin

    raemin Formula 3

    Jan 16, 2007
    1,825
    Lyon (FR)
    Full Name:
    R. Emin
    I think you should replace yourself the oil filters at least once, and you will understand what everybody's talking about. It is hard to imagine that oil filters are sealing the cooling circuit, but take our word on that: when you remove the filter and see the coolant this is just crystal clear.

    So at the risk of repeating myself and what everybody else said so far: replace those filters and see for yourself ...
     
  18. Ewan

    Ewan Karting

    Jul 5, 2015
    222
    Dorset, UK
    Yep - changed the oil filters every year for the last three years as part of the annual servicing.

    What I do know is that the oil mixing with the water isn’t what I want, and it isn’t going to fix itself! To my mind, this situation is only likely to get worse. So instead of waiting for an escalation, I may as well just deal with it. Financial pain aside, it’ll be good for the car.
     
  19. Bill26

    Bill26 Formula Junior

    Jun 19, 2005
    255
    Australia
    Full Name:
    Bill Murdoch
    Ewan,

    It's a good decision. Just as long as you understand it will likely cost a lot more than you expect.

    Good luck!

    WM
     
  20. Schumi

    Schumi Formula Junior
    Owner Silver Subscribed

    Jun 5, 2002
    827
    Missouri
    Full Name:
    Daren
    I am continually amazed by those who ask for opinions on this board, have them quickly and correctly answered by actual experts (Rifledriver & others), only to see that those opinions are tossed aside - even when there are easier, cheaper, better methods of determining the real problem.
    I guess we all get different things from this forum, but to ask a question, get a knowledgeable answer, and then ignore it is something I don't understand.
     
  21. Ewan

    Ewan Karting

    Jul 5, 2015
    222
    Dorset, UK
    No opinions tossed aside. All considered. But the water pump and rad have already been checked and ruled out, and in the opinions of the two Ferrari trained specialists that have inspected the car, the O rings are unlikely to be the true/sole cause of the issue I have (apparently). But it’s great to be able to come to forum to ask for additional opinions, as you never know what you can learn (especially for me, as a non-mechanically minded person). So I am grateful for the suggestions and assistance.
     
    Schumi likes this.
  22. Newman

    Newman F1 World Champ
    Consultant Owner Professional Ferrari Technician

    Dec 26, 2001
    14,092
    Canada
    Full Name:
    Newman
    10Xhobby and Rifledriver like this.
  23. Ewan

    Ewan Karting

    Jul 5, 2015
    222
    Dorset, UK
    As a mechanic, you must indeed find that annoying. Which is why in this particular case I ended up following exactly the advice of the two mechanics that have (independently from each other) physically inspected the car.

    So, I asked opinions from a variety of sources, and received a variety of answers. I ended up choosing the course of action I believe will be best for my car. That seems a perfectly reasonable way to behave. But if you think differently, so be it.
     
  24. roger21

    roger21 Formula Junior

    Aug 13, 2015
    262
    France
    Full Name:
    Stéphane
    Just my 2 cents as a non professional and not even amateur mechanic...
    Ok, lets say I am Ewan and I get answers from members that I trust and I am very happy with them but then:
    I haven’t got the knowledge/tool/room to give it a try and do the job by myself so I would go and see my mechanic and tell him “I have had interesting opinions”.
    And what if he says “I don’t think they are right”??
    And imagine what he would think if I tell him those ideas comes from a chat! (Ask me how I know!!!!)
    Remember that Ewan is talking about professional Ferrari mechanics ...

    I really understand and respect your mechanics opinions. You are able to know why and how to do this and not that but it’s really not so easy for people like me that don’t know anything about it.
    As I say, just my 2 cents to help to understand each other’s opinions...✌️
     
    raemin likes this.
  25. Newman

    Newman F1 World Champ
    Consultant Owner Professional Ferrari Technician

    Dec 26, 2001
    14,092
    Canada
    Full Name:
    Newman
    The point is its nothing to replace the oil filter housing seals or even take just a moment to look. Diagnosing without digging is a mistake. Yes it could need a head gasket but they are guessing and even a blind squirrel finds the odd acorn.
     
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