Yes, you are correct. Dissimilar metals in an electrolyte make a battery, and one of the electrodes will erode. I was assuming that at the age of the vehicle the coolant would still be in good shape. I recently looked up the service life and if memory serves, replacement of coolant is called for at 10 years.

I still don't see how anything less corrosive than salt water would do that to the heads of the valve cover bolts, but all I've got to base that on is the picture.

 

When coolant leaks onto hot surfaces the water and some of the chemicals evaporate, leaving a concentrated mixture that is corrosive.

 

Having the same issues on my 2014 V-6 F-type -S. Doing, tranny and diff maintenance, also updates to plumbing and supercharger coupler. I have 2 valve cover bolts in middle on passenger side from roof vent corroded pretty bad. Not leaking just bothersome because car is flawless otherwise. Bought it new only 27k mi and babied. Roof vents fixed with 2 small pieces of silver A/C duct tape now but wondering if I should try and repair the 2 bolts ? They don't just come out to replace. I tested a good one on corner and found they are held in place by the valve cover gasket. So I have not attempted to remove them yet as they could strip or break. Not sure the extent of the corrosion on collets underneath. Does anyone have any suggestions as to remove them without removing valve cover, and should I just leave them for now ? I'm right there and would feel better to fix them. A Jag master tech told me since they aren't leaking yet to "just leave them", but it is bugging me. I started this because of a small coolant loss and suspected the Y-pipe under supercharger, wasn't. It was the dang water pump @ only 27k miles ! I love this car but now thinking twice about keeping it. Any suggestions or advanced knowledge appreciated. New member and love the forum. Thanks

 

Dpark,

I replaced the pipes at 14K due to the comments on this forum. I have never owned a jag before so learning failure points was a high priority. My 2017 had the older style pipes and even though the car had low milage the concern was that the coolant system was five years old so ended up replacing everything myself.

There are many weak points in regard to the coolant system. When I removed the hose that connects to the coolant reservoir it basically broke apart and was brittle. Many of the hoses were found to be extremely soft when compared to the new replacements showing material degradation.

I would recommend going through the coolant system at five years and not waiting for a problem to occur or at least conduct periodic inspections and if the coolant has to be consistently added to maintain proper level stop driving the car and fix the issue also if your car has the split seem pipes it is my opinion that they should be replaced now as pipes are cheaper than engines and many members including myself could walk other members through the process.

 

WaveyDavey,

I would order new bolts and soak the old ones with PB blaster or something similar to aid in removal. Recommend pull one bolt and replace at a time reducing the opportunity for the gasket to move around. I had to pull the front three valve cover bolts for the driver side to remove the timing cover due to an oil leak and had to use moderate force to pull the bolts out after they were untreaded due to the grip from the valve cover gasket.

Your car has low milage, but the coolant system is nine years old, and many manufactures recommend 10 year or 100k mile replacement. Defiantly recommend changing the small pipe that connects to the water pump from the oil cooler and order an extra o ring because if memory is correct the small pipe came with one o ring but two are needed.

Lastly before you put the car back together rinse and clean everything using distilled water. I bought a few gallons and flushed the valley of the engine while wiping everything down due to coolant spillage from component removal. If you do decide to use a cleaner make sure the salt content is low and then use the distilled water as a rinse.

 

Ok, will do. I pulled one on the corner but couldn't get it through the valve cover gasket. I was afraid to really pull hard on it, should I ? I just want to make sure I can get them thru after hopefully getting them loose. I know the compressed valve cover gasket is holding them down, so how do I get it through or out, pull them really hard, or loosen more of them to decompress VC ? Do i need to loosen them across the top first ? I don't want to try and get to the bottom bolts if I don't need to or completely remove the valve cover. I'm starting to get a little nervous about how much I have taken it apart already. I would love to just replace the 2 rusted bolts if possible without removing the cover. And yes I have soaked them in PB Blaster thoroughly for about a week now and hopefully they will just back out easy after getting a smaller socket down on them. Also I did replace every piece of plumbing including the little plastic line from top of coolant tank you mentioned above. All of them except the one pipe across the back, do you suggest i replace it too ? it looks fine. And thanks for the tip on the 2 O-rings on water pump, I was wondering about that. Oh also, I just removed the 2 dowels in bottome of supercharger completely as they were a real pain and think I can line it up using the intake holes when I put it back together, do you think that's ok ? Thanks for your reply. I've seen a lot of different people do this job now on YouTube etc, and this thread is by far the best, cleanest and most comprehensive. Just awesome really !

 

WaveyDavey,

I would only loosen the bolts you intend to remove and or replace. There is no need to remove the valve cover and to remove the valve cover the injectors come into play which requires special tools. The bolts will come out just ensure they are completely unthreaded, and you can tell by the bolts ability to slightly move back and forth. I felt the same way and was worried about breaking something. The front valve cover bolts have a metal cylinder/spacer that the bolt goes through that I believe is to set the height and they were challenging to remove due to the suction created from oil.

The bolts that you are trying to remove should come out after unthreaded just take your time and also note your angle when pulling them straight out. Once removed the tech manual says to coat all newly installed fasteners with a light coat of oil on the threads.

I replaced the crossover pipe in the back when I had the super charger out due to ease of installation. I didn’t want to put everything back together just to have another leak down the road and have to remove the supercharger again. The cross over pipe is another weak point in the coolant system. What do you mean when you say, “I just removed the 2 dowels in bottom of supercharger completely”? Those will have to be reattached and once done the super charger will only go in one way so you will not have to align anything as the dowels sit in the cavity machined into the block. I did coat mine in anti-seize for rust protection.

 

Well, I absolutely cannot get any the Valve cover bolts to let go of the gasket and yes they have a little collar attached to them that I believe is being held to the valve cover by the gasket. I took them completely loose, swirled them around in circles, pulled them in every direction incl straight up etc, the collar will not come thru the gasket. I'm thinking now just leave the 2 corroded ones until the gasket goes bad. I've seen one mech online do it and said the valve cover gasket must be removed to get the bolts out. Do I understand you correctly, you were able to get them out though ?
And I agree, I think I will go ahead and order the rear pipe for piece of mind as it is the only thing that I will not be replacing if I leave it.
As for the 2 supercharge dowels, it destroyed them removing them as one was stuck in motor and one in the SC. I don't think I want to use those again and believe i can line it up by just feeling thru the intake holes but I will consider that some more before reassembly.

 

WaveyDavey,

When looking at the front of the valve cover (driver side) there are three bolts that hold the front of the valve cover. Two of the bolts I removed have studs that stick out and the other bolt sits flush. I removed all three to gain the ability to remove the top timing chain access cover due to a lower oil leak. These are the only bolts I have ever removed from the valve cover, but they did come all the way out. I would assume that the other valve cover bolts would be similar.

If you can post a picture of the dowels as this is something I did not have to deal with. My supercharger came out with no issue. If you have one stuck in the block and one in the supercharger there may not be a choice but to reuse them unless you take the supercharger to a shop for removal. The dowel in the block could possibly be drilled out but I would need to see what you are working with, again when I loosened the coolant manifold bolts the whole assembly lifted up.

As for the intake bolt if you do not want to take any risk, I would just clean them and treat with a rust preventative until you decide to do the injectors and at that time replace the gasket.

 

Yeah that's what I decided too. I went ahead and tried it again, I loosened all of the ones across the top on the other side to test it and none of them would come out and really put some force to them. So I've decide to just leave them as the Jag mech had told me originally and wait until it's leaking and remove the valve cover completely for new gasket etc.
As for the dowels, I machined new ones with a high temp composite plastic, treated them w/ anti seize and feel good about having them instead of the metal ones as they will not corrode or get stuck the next time and yes the dowels even though I don't feel they are completely necessary and only there to assure correct alignment during the original assembly does make me feel better knowing it will be straight and correctly positioned without a lot of extra fuss to get it straight.
Different subject, but that transmission service was a real joy setting that fluid level aye ?
I'm kinda surprised by this car and how hard some things are to work on. I have worked on every kinda car in my 60 yrs and I thought the Porsche's had a rep for being tough, but these things are right there with them. Lol
Well thank you very much for your advise and insight and I look fwd to future interactions here on this forum.
Dave