Coolant loss on 99 boxter

[Bulwinkle]

125 K miles on boxter. used about 1 quart of coolant every 25 miles.No leaks. No ck engine light. Independent shop did pressure test,leak test.Said probably not head gasket.Seems to miss when engine is hot.What is your suggestion?

[txd0mask]

Had the same problem. If you have the original coolant cap you probably need a new coolant cap. Porsche has updated the original boxster's multiple times due to the fact that they caused coolant to leak or evaporate.

[harryrcb]

If you have no leaks externally then you must have a leak internally. It is either getting burned up in the combustion chamber or intermixing with the oil. Drain your oil and look for any signs of water contamination. If nothing then you must be burning it up in the combustion chamber.

[Bulwinkle]

tHANKS, I JUST REPLACED THE COOLANT TANK(AND CAP).i AM SUSPECTING THE HEAD IS CRACKED. I AM NEXT PULLING THE PLUGS TO CHECK.

[Bulwinkle]

I agree . I will pull plugs to check.I guess I am in denial. I suspect a cracked head. Would really like to have a book on engine rebuild. Am used to the Haynes type book,I do have 101 Projects book and Bentley Service Manual.....no help!

[tomk]

IMHO, 1 qt of coolant every 25 miles is a serious leak and if it was external then it would/should be detected somewhere in a carpet or on the ground. You might want to buy/borrow a tool for measuring coolant pressure. The book supplied with the one I bought gave excellent tips on how to read head gasket failures on the pressure gauge with the engine running and up to temp/press. Good Luck!

[JFP in PA]

Originally Posted by Bulwinkle

I agree . I will pull plugs to check.I guess I am in denial. I suspect a cracked head. Would really like to have a book on engine rebuild. Am used to the Haynes type book,I do have 101 Projects book and Bentley Service Manual.....no help!

There are a couple good reasons why no one (other than Porsche) has published a rebuild guide: Very few actually get involved once they find out what is required. These rebuilds require a lot of single use fixtures and tools that you would either need to buy or fabricate. Cost estimates to buy the needed items once ran into the many thousands of dollars. The assembly process is not straight forward due to the design of the split cases and crank carrier, requiring specific knowledge as well. This is why those shops that do rebuild them, and do it well (there are some real shysters out there), get a lot of money and have a very long waiting list.

[Bulwinkle]

Thanks JFP in PA. I guess you can tell I'm new with a Boxster. I have had a lot of experience with engines of many brands. 6 of them were Porsches. I had no idea when I got this car that information was so inadequate for a lay person(shade tree) with experience to work on these. I absolutely will not take it to Porsche to be fixed. The purpose of having a car like this is to challenge myself to make the repairs. If I cannot,I will sell the pieces or convert it to an engine that CAN be worked on.
From the looks of many threads on here, owners have the same problem with these cars and are left to find their own solutions.Thank God for the aftermarket to keep cars running.

[j911brick]

Its not that big of a deal to get into these motors. Its new, and its different, but so was the 911 at one time. Yes, you will need to spend about $1k on tools, and make some as well, but I'm sure you can resell them when your done. Check Youtube; there is a guy on there who has a series on rebuilding the M96 motor.

[Bulwinkle]

Did pull plugs. First I ran it for awhile and re bled the coolant system to make sure all the air was out. Took for a short ride and began to miss. Code read miss in #2 cyl. This happened two weeks ago, code read #3 cyl. #3 plug was the only one with deposits on it, other 5 were clean and white.
BTW, the oil and coolant are clean and new. I suppose next will need to pull engine and heads whether or not it is gasket or cracked head???

[harryrcb]

you are on the right track - keep us posted

[Bulwinkle]

I think I have all the diagnosis that tells me the area needing work. I have begun the disassemble and extraction procedure.I feel at this point that there is no turning back.I like the car (not love it). By the time it is fixed I will be very deep in the relationship. I suppose it is too late to get a prenuptial agreement??

[Bulwinkle]

Engine is OUT. Pulled right side head. Took a lot to find a head bolt tool that would not break Ended up with Torx tool from Sears. Still needed to drill out 7 bolts! Found rear cylinder with crack in cyl wall. I guess motor is junk Am shopping for replacement. I may sell 944 to buy motor.

[derfo]

Originally Posted by Bulwinkle

Engine is OUT. Pulled right side head. Took a lot to find a head bolt tool that would not break Ended up with Torx tool from Sears. Still needed to drill out 7 bolts! Found rear cylinder with crack in cyl wall. I guess motor is junk Am shopping for replacement. I may sell 944 to buy motor.

Hi Bulwinkle
Check with LN engineering to see if they can do a re sleeve for you first.

[Wayne 962]

Man, the certainly don't build them like they used to!

-Wayne

[AL MEREDITH]

Looks like a slipped sleeve. Look for a yellow paint mark on the clutch end of the broken side . It seems the factory marked the cases that they re-sleeved. Been there, L&N will repair the case and supply it with a "big bore" J&E pistons are supplied to make it a 2.7L. He supplied mine with big pistons for use with a 2.7 crank making the engine a 2.9 L . Len Hoffman of HAM is reworking the 2.7 heads now, we'll have some Dyno numbers in a couple of months.

[Wayne 962]

Originally Posted by JFP in PA

There are a couple good reasons why no one (other than Porsche) has published a rebuild guide: Very few actually get involved once they find out what is required. These rebuilds require a lot of single use fixtures and tools that you would either need to buy or fabricate. Cost estimates to buy the needed items once ran into the many thousands of dollars. The assembly process is not straight forward due to the design of the split cases and crank carrier, requiring specific knowledge as well. This is why those shops that do rebuild them, and do it well (there are some real shysters out there), get a lot of money and have a very long waiting list.

Hmm, I agree with JFP almost 100% of the time, but not entirely on this. Everything that you said above is true, but it's also true with all of the air cooled motors as well. I actually think they are trickier to rebuild than these water motors because they are very unique. If I hadn't written my aircooled rebuild book, there would be a lot of mystery out there regarding rebuilding those. I have sold a *ton* of those books (I think almost 50,000 or so), so that does indicate that there is a market.

From a parts perspective, there are no real internal engine parts available for rebuilding. It's a chicken / egg problem, as the more people rebuild, the more the market will provide the parts. It's on my list to eventually put together a rebuild manual for these engines - I hear that Jake is already working on one himself, so if he does it first then I probably won't bother. I think the lack of information / a good rebuild manual is also a chicken / egg problem - if one existed, I think more people would tackle it.

-Wayne

[Bulwinkle]

Thanks all. It appears from a financial standpoint an engine swap makes more sense to me. Only because the car is now worth what I have in it. It will actually not be worth more no matter what I do to it.I have a line on a Boxster 2.7 2001 with reasonable miles on it.
Just a note. The engine came out quite well by myself-for the first one.

[healthservices]

Part your car out and save the trouble. Just buy another after it is all parted out.

[EBS_Don]

Be careful when trying to go to a 2.7 liter from a 2.5. The main issue is with the intake. The 2.5 intake does not fit the 2.7 heads and the 2.7 intake uses an electronic throttle body. A custom adapter will have to be made.

I had a customer go through this exact scenario with his 1998 2.5 where the cylinders were slipping. Not enough for a catastrophic failure but it acted like a head gasket. It was a shame because the engine was in excellent shape otherwise. We simply found a really nice set of case halves that were a good match for his pistons and rebuilt the engine. almost 20k miles later and he is still very happy with his car and the engine. In fact he just stopped in this morning to thank me again for the good service!