Miker7 Posted August 7 Share Posted August 7 So my k series is overheating, only did a couple of miles and didn't get to the red. (cue swear words). I'm convinced I've got an air lock in the heater and having run the heater i've introduced the air lock into the system. I did have a weep past one of the joints a while ago so i can guess how the air got in. Had a refill of the car last night. Had it jacked up, have a bleed t near the heater undid and redid the radiator bleed, went round a few times and its a faff. I'm also certain I've still got air by the heater. This morning I'm wondering, why don't we just remove the header tank, lift it up 6 + inches so its absolutely the highest point and fill the car. The open the bleed values till water comes out, then run the car, check levels and refit the header tank. Why do we faff with jacking the car up etc? (yes that was a deliberate click bait headline, I've got tonight to fix this before the pub meet tomorrow and my wife already has a list of jobs for tonight) Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted August 7 Member Share Posted August 7 Should work. But of course it's necessary not only to bleed at the highest point overall but also at any local maxima. Jonathan PS: We know that it's harder on some Sevens than others... cue what's worked for whom... and the hole in the thermostat. ; - ) Link to comment Share on other sites More sharing options...
Miker7 Posted August 7 Author Share Posted August 7 Got the hole in the thermostat - at the top of the thermostat as well. I had the hydraulic jack maxed out on lift on the front end & had a piece of wood between the different crossmembers so i could jack it up further towards the rear of the car to increase lift. Its all ridiculous when (in my head) undoing one bolt and lifting up the header tank solves all these issues. (I'm a bit miffed about this as I'd got a good excuse for a drive last night that had to get aborted and use the tin top instead) Link to comment Share on other sites More sharing options...
Area Representative Paul Richards Posted August 7 Area Representative Share Posted August 7 I doubt lifting the expansion tank will help. My experience is that the overheating is caused by an airlock adjacent to the thermostat. That’s why a hole in the top of the thermostat is recommended to allow the air to pass through and hot coolant to come in contact with the stat and open it. The idea of raising the front of the car is to raise the angle of the thermostat housing to help air escape through the hole. Once you have filled via the expansion tank I find it helps to trickle coolant into the bleed T and keep shaking the hose to help it flow towards the stat and keep repeating until no more coolant can be added. Sometimes refilling goes easily, other times it can be a real pig. It just seems that sometimes you’re lucky. For some reason I’ve always found the 1.4 engine the worst to bleed. Good luck with it. Link to comment Share on other sites More sharing options...
PROBE2 Posted August 7 Share Posted August 7 After years of trying to perfect the process I follow the same approach as Paul above and works well for me. Ensuring hole in thermostat and bleed tee on top heater hose. Open heater valve fully, fill expansion tank to level and put cap on, fill radiator fully then backfill by topping up via bleed tee, whilst holding the top heater hose as high as possible, coming back a few times over a couple of hours to top up. 1 Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted August 7 Leadership Team Share Posted August 7 I do a similar method but fill completely via the bleed tee .... and SLOWLY! When it's coming out of the radiator bleed I refit the bleed bolt, then when the level is right in the expansion tank I refit the cap. I keep going until it's backing up at the bleed tee. No lifting of the front of the car, expansion tank or anything else, and it works every time. Stu. 1 Link to comment Share on other sites More sharing options...
Miker7 Posted August 7 Author Share Posted August 7 Where are people's bled tees. It's very hard to get mine higher than the heater without it feeling like the heater pipe is going to break. Do I need to swap the heater valve and the bleed tee? Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted August 7 Member Share Posted August 7 IIRC further from the valve allowing more elevation. Jonathan Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted August 7 Leadership Team Share Posted August 7 Same place as yours Mike although I suspect my hose from the bleed tee to the thermostat housing might be a little longer, the bleed tee pretty well sits at the high point all the time. (and yes that is a Leffe glass strapped to the ecu, we stayed at the Leffe Museum in Dinant and didn’t have any boot space left for the freebies!) Stu. Link to comment Share on other sites More sharing options...
Miker7 Posted August 7 Author Share Posted August 7 Ah, different heater connection. Perhaps what I need to do is adjust the pipes from the heater so they don't angle down. Plenty of think about. Still think temporarily lifting the header would work, but I'm loath to go against the tide of conventional wisdom with so little time to play around. 1 Link to comment Share on other sites More sharing options...
grumpy the 7th Posted August 8 Share Posted August 8 put a longer bit of heater hose onto the tee so you have more slack to lift up high. You don't want to be pulling the pipe too hard or you'll end up pulling the straight connector connecting the 2 hose ends under the plenum out. (I've got the tee shirt) 🤭 Link to comment Share on other sites More sharing options...
Miker7 Posted August 8 Author Share Posted August 8 Interesting comment - its just made me look at my picture compared to SLR No 77's. My top hose goes to the exhaust side of the engine. His goes to the inlet side. I can't really see it making a difference - it will still circulate around the heater matrix but ..... it is different! Link to comment Share on other sites More sharing options...
Wrightpayne Posted August 8 Share Posted August 8 (edited) Inlet side will be filling from low down the block. Exhaust side will fill cylinder head down and into the top of the rad. I think the former is better. A hozelock tap connector screws onto the bleed tee so easy to knock up a fill tube with height! Edited August 8 by Wrightpayne 2 Link to comment Share on other sites More sharing options...
Wrightpayne Posted August 8 Share Posted August 8 And connect the hose for a power flush!! Link to comment Share on other sites More sharing options...
Area Representative Paul Richards Posted August 8 Area Representative Share Posted August 8 1 hour ago, Miker7 said: Interesting comment - its just made me look at my picture compared to SLR No 77's. My top hose goes to the exhaust side of the engine. His goes to the inlet side. I can't really see it making a difference - it will still circulate around the heater matrix but ..... it is different! Top heater hose normally goes to thermostat. Yes it will circulate, but it won’t help clear an air lock next to the thermostat using the method described by myself and SLR 77. 1 Link to comment Share on other sites More sharing options...
Miker7 Posted August 8 Author Share Posted August 8 1 hour ago, Wrightpayne said: A hozelock tap connector screws onto the bleed tee so easy to knock up a fill tube with height! Thank you. Id been wondering what the thread was to 3d print a header / filler funnel connected to the tee. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now