TomGaval Posted November 11, 2013 Share Posted November 11, 2013 Had the car at the track this weekend and ran the first 3 sessions on Saturday with no issues. At the end of the 4th session, as I was returning to paddock, I noticed a bit of fluid on the brooklands and the vents in the bonnet. Temp gauge never showed any issues. I removed the bonnet to find that expansion tank was full and leaking coolant. Lower hoses seemed to be somewhat cool. So I opened the bleed tee and flexed the lower hose and had some air bubbles released. I drained out the excess coolant and brought the level back to the fill line. Ran the car in the paddock for a a bit, saw the temp go to about 80 and then the temp dropped a bit and the level in the expansion tank dropped, I Stopped and added back the coolant that I had originally removed and it brought the level back up to the fill level. Thinking all was good I ran the next 20 minute session. Temp stayed around 60 ish all the time, but when I checked the coolant level was now up to the top of the expansion tank. Drained again, checked for air again, filled to the fill line and drove around the paddock again, Same thing, temp comes up to 80, drops down to 65 ish and the coolant level in the expansion tank, again drops a bit. I decided not to fill it to the fill line, Ran the next 20 minute session, temps stayed constant, and when I checked in the paddock, the coolant in the tank was now up to the fill line. I'm confused now as for the last 12 years, I never had a issue. Any thoughts? 1.8L Dry sumped K. Thanks Tom Link to comment Share on other sites More sharing options...
TomB Posted November 11, 2013 Share Posted November 11, 2013 Sounds like it could be the head gasket, maybe a slight leak between one of the cylinder and coolant runs that only appears when used hard. My 1.4k had similar symptoms and it turned out the plastic head location dowels had distorted and extended hard running would pressure the coolant and spit it out of the expansion tank. Either way its a head off job. Alternatively it could be an airlock which will be easier to sort! Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted November 11, 2013 Share Posted November 11, 2013 Check the one-way ball valve inside the head. Remove the small hose that connects to the expansion tank and push a screwdriver into the spigot to see if the ball moves Edited by - SM25T on 11 Nov 2013 14:57:34 Link to comment Share on other sites More sharing options...
TomGaval Posted November 11, 2013 Author Share Posted November 11, 2013 I have one more track weekend to go this weekend. I'll try to bleed it again before I go and see what happens. Could it be a faulty expansion cap? Tom Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted November 11, 2013 Share Posted November 11, 2013 They can fail and are cheap and easy to replace. Link to comment Share on other sites More sharing options...
Englishmaninwales Posted November 11, 2013 Share Posted November 11, 2013 Coolant airlock, cap failure, cylinder head gasket failure or cylinder head porosity. Last two ☹️ Link to comment Share on other sites More sharing options...
tin duck dave Posted November 13, 2013 Share Posted November 13, 2013 Had very similar symptoms from a tiny failure on head gasket sealing ring by one cylinder - just pressurised expansion tank when worked hard on trackdays but fine in normal road use. Link to comment Share on other sites More sharing options...
TomGaval Posted November 13, 2013 Author Share Posted November 13, 2013 Just did a major massage of the hoses and topped off the hose at the bleed tee. Replaced the expansion tank cap and will take it to the track on Saturday and Sunday and see what happens. I'll keep an eye on the temp during the time on track. So should I run with the coolant right up to the fill line or drop it down slightly to start out? As the head has never been off, what are the steps to changing the Head gasket? I'm going to pull the engine over the winter to change the clutch, so I assume it will be an easier job with the engine out. What gasket is recommended? What other pieces and parts will I need? Does the it need to be peened? Skimmed? No leaks from the gastket so far. Will running it this weekend damage it assuming I keep the temp within range and the fluid at the correct level? Just planning for the worst. Hopefully it will be fine this weekend. Thanks in advance guys. As one of very few if any other K Series over here in the states, I doubt I'll find anyone that knows this unique engine. Unless Oily wants to take a little winter vacation. 😬 Tom Link to comment Share on other sites More sharing options...
Mark Durrant Posted November 13, 2013 Share Posted November 13, 2013 Tom If you have this type of expansion tank then fill to the seam not the top mark. Link to comment Share on other sites More sharing options...
TomGaval Posted November 13, 2013 Author Share Posted November 13, 2013 That's the one. Will do. Thanks Tom Edited by - TomGaval on 13 Nov 2013 21:57:00 Link to comment Share on other sites More sharing options...
Croc Posted November 14, 2013 Share Posted November 14, 2013 Quoting TomGaval: As the head has never been off, what are the steps to changing the Head gasket? Tom 1) Go to local supermarket 2) Buy a pack of sliced swiss cheese 3) Remove head 4) Lay cheese evenly all over block 5) poke holes in cheese with screwdriver for pistons, oil and water galleys 6) put it all back together and hope it runs for another year or buy a Duratec engine that is reliable See you this weekend Tom - hope my car is finished in time to run with you! Link to comment Share on other sites More sharing options...
Nick Woods Posted November 14, 2013 Share Posted November 14, 2013 This sounds a lot like my K-series head gasket failure from a few years ago. Driven gently-ish it was fine but when pushed hard the coolant level would rise. If I stopped the engine before it overflowed, let it cool down and bled out the excess gases the level went back to normal. It took several weeks and 4 tests for gases in the coolant before it was confirmed as a gasket failure. The full story is here Link to comment Share on other sites More sharing options...
Area Representative paul richards Posted November 14, 2013 Area Representative Share Posted November 14, 2013 First step is to change the cap on the expansion tank. Quality is poor and they produce the symptoms you outline. They only cost a couple of quid. Well worth trying first. Link to comment Share on other sites More sharing options...
TomGaval Posted November 14, 2013 Author Share Posted November 14, 2013 I went back thru the archives and read all the posts I could find and yes Nick it does sound all to similar. I've replaced the cap, bleed the system and will run it again this weekend and let you know how it responds. I wonder what the cost will be to ship the engine over to Oily. As for you Croc, we'll see if you can keep up with me, Just wish that I did have the Duratec with the extra 80+ hp gap you have on me. Doesn't take much talent to catch me on the straights you girl. 😬 😬 😬 see you on Saturday. Tom Link to comment Share on other sites More sharing options...
TomGaval Posted November 14, 2013 Author Share Posted November 14, 2013 Ok, changed the cap, opened the heater valve, unscrewed the expansion tank cap, topped off the hose at the bleed tee andstarted the car and removed the radiator bleed screw. Coolant came out of the bleed screw hole, sputtered a bit which I took to be air, then steady stream. Replaced and tightened bleed screw cap was back on the expansion tank. temp cam up to about 60 and stayed steady. expansion tank coolant dropped very slightly, after 10 or 15 minutes no change in temp. Turned off car, top of radiator was hot, bottom hose barely warm. What did I do wrong? What do I do next? Tom Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted November 14, 2013 Share Posted November 14, 2013 Nothing ! Bottom hose won't get hot until thermostat opens and whole system up to temperature. At this time of year this can take some time. Is your bleed tee at the highest point ... so you know the air rose to that point ? Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted November 14, 2013 Share Posted November 14, 2013 Consider doing the cooling system mod as detailed in LF September 2012. Very cheap and easy. I have a PDF scan if needed. BlatMail me your e.mail address. Fast warm up and good regulation. Easy to get air out too. Link to comment Share on other sites More sharing options...
TomGaval Posted November 14, 2013 Author Share Posted November 14, 2013 Yes, bleed tee is at top of the heater hose connection. Blat mail sent. Thanks! Tom Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted November 14, 2013 Share Posted November 14, 2013 Nothing landed ..... yet Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted November 14, 2013 Share Posted November 14, 2013 Still nothing. Sent you a BlatMail with my address in. Link to comment Share on other sites More sharing options...
TomGaval Posted November 14, 2013 Author Share Posted November 14, 2013 Got your email, have sent you a reply with my address. Thanks Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted November 14, 2013 Share Posted November 14, 2013 PDF on the waysin a few minutes Link to comment Share on other sites More sharing options...
TomGaval Posted November 18, 2013 Author Share Posted November 18, 2013 Well, I had the car out on track this weekend, running both Saturday and Sunday. Prior to going I bled the system and replaced the expansion tank cap. No issues Saturday, No issue on Sunday until I came in on the last session of the day. Car was running great all day, I kept an eye on the temp gauge on every straight on every lap and it was steady and never went past 80. In fact under speed with the airflow it stayed around 65. When I was pulling into the paddock I noticed a misting on my brooklands. When I pulled the bonnet and nosecone, I could see that the expansion tank was now full and that some of the coolant had splashed out. So, More confused than ever. How does it run for almost 2 days with no issues and then puke? I was pushing really hard the last session as I tried to stay ahead of a GTR, with 850hp, but I can't say that I was just crusing all the other sessions. Done for the season, and I am pulling the engine to change the clutch, so does any one have a step by step instruction or video of how to change the head gasket on a K Series? There aren't many if any over here, so This will be new territory for my mechanic who specializes in BMWs. He's a racer and good wrench, and has maintained my car for the past 5 years or so, but nothing with this Motor. Also what parts do I need to order in addition to the gasket? Head bolts, dowls, etc. This motor was built by QED in 2000 and has been great, being a trackday car pretty much since I assembled it. So it has spent most of it's time in the 6000 to 7000 range as I've tried to use 7k as the max rev limit just to be gentle on it. 😬 Thanks again for the help. Blatchat is the best! Tom Edited by - TomGaval on 18 Nov 2013 14:30:14 Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted November 18, 2013 Share Posted November 18, 2013 Do the coolant mod while you are playing with the engine Link to comment Share on other sites More sharing options...
TomGaval Posted November 18, 2013 Author Share Posted November 18, 2013 It's on the to do list. Thanks Ian. Link to comment Share on other sites More sharing options...
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