Engine coolant leak :(

Level 6 User Joined: 20 Jun 2004 Posts: 155

Yup thanks for the advice - I was already thinking that the rear flexi pipes are prolly knackered, since I have just had the front ones done for the MOT (which involved new metal pipework back to the MC as well). I just hope the union nuts on the rears haven't seized like the fronts did, even though they probably will have Sad

I was thinking about how I could check that it wasn't the servo - I assume that if I disconnect the vaccum hose from the inlet manifold to the one way valve, that will disable the servo and I will be able to drive around a bit and see if the same problem recurrs. The funny thing is that I can 'reset' the brake pedal feel by pumping the pedal with the engine off, which made me suspicious of the servo system. But then I can't quite get my head around the nuances of potential leaks between the MC and servo setup so I'm probably wrong! Also I can't quite see how the servo could have any effect on the travel of the brake pedal - it should only be able to make the pedal heavier (when buggered) or lighter (when working).

Ahhhh this is making my brain hurt Smile

I'll do the easy stuff first then start getting complicated I reckon!

After all I've got to get the beast running again sans water leak first which was the whole point of this thread Confused

I have little use for brakes at the moment Laughing

Cheers
Alex

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

the servo like you say should only affect the weight of the pedal.

Not the travel or the pedals effectiveness.

Get new rear cylinders and if need be new pipe, they are not hard to make up and tend to be cheap enough.

Decent brakes make a car. After all no use if you can accelerate like a bullet but can't stop.

Level 6 User Joined: 20 Jun 2004 Posts: 155

Well I was going to remove the carb today but of course the one torx bit I need is the one I don't have Sad

I've got a mate coming over later with one hopefully, but it will be dark by then so another day passes...

One thing I did think of is regarding the core plugs - are they screw in or just hammer-in? I'm just wondering how you can get the old ones out - can you push them out from inside the manifold or do you just yank and scrape them out from the outside? Similarly the hose stub - is that just a push fit arrangement or is that screw in?
Of course, if they are all corroded away then its not a problem but I expect some will be and some won't.

BTW I totally agree with you about good brakes making a car! When you are piloting a ton of steel around one thing you really don't want to be having any doubts about is your ability to stop it when you need to Smile

Cheers
Alex

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

a push fit, nay my friend use not these common terms. Its an interference fit!

To remove the core plugs you need to batter a hole in them and lever them out, a self tapping screw can be used but takes time.

To fit them I use a socket thats a loose fit in the plug them bang it in with a hammer.

The stub, use grips to twist it out, if its rotted away flush then a screwdriver can be belted in uder it or use a hacksaw blade to cut a slot on it.

Brakes are improtant, Alans GTT brakes are cack, I improved the red un's brakes today by freeing off siezed sliders.

Level 6 User Joined: 20 Jun 2004 Posts: 155

OK well I had a play today - got the carb off relatively easily, but I cannot shift any of the manifold bolts. They seem to all be well seized and any attempt to turn them just starts to eat the bolt away, so it will probably be a garage job Sad

Which means I got to decide whether to bother or just scrap the car and get another since it may well be an engine out job I reckon which means another wad of money.

I did (I think) discover the problem at least - assuming I am right and there are only 2 core plugs, then one of them is leaking like hell. I assume that when you feel under the manifold, the two big holes you can feel are the core plug holes? One of them is leaking big time either way. The hose stub on the other hand looked in remarkably good condition - when I removed the hose, I was presented with a nice shiny steel tube, so I assume that is OK, especially as it isn't leaking at all. Ironically it probably would have been better if it was that that had gone cause I could have done that in situ.

So the next question is: is there any way to get the core plugs out with the manifold attached and the engine in the car? It looks like the alternator is in the way for a start, which would make getting them out tricky, and I'm not sure about how you would get enough force to knock the new ones in, but aside from that is it doable from underneath? Chris you said that using a self tapping screw takes time, do you mean that it's hard to get the screw to bite into the core plug, or just that its fiddly? The duff plug seems to be squirting a thin squirt of coolant out at an angle of about 30 degrees below horizontal when I squeeze the top rad pipe, so I assume there is a fair amount of the plug still in there to screw into. One other thing I wanted to check was how far the core plug goes in - does it just go from the outside of the manifold into the water jacket, or does it go all the way into the actual inlet pipework?

How long should it take a garage to do do you reckon? What would be a fair price? I'm not sure if I'm up to the task on this one Smile

I don't know why they don't just use some kind of liquid sealant stuff to seal the holes instead of iron plugs - seems like a much better way to me!

Cheers
Alex

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

well if things arew going arse up then leave the manifold on.

why did you try and loosen them anyway with coolant still in the system That would have just gone int the engine making more work.

Anyway look on the side of the cyl head, see where the dizzy is? See how theres a round hole with a small bucket in it? Thats a core plug.

You could get it from underneath but it would be awkward at best, but if you could try and get a screw into it by reaching under you may be able to pull it out then using pliers.

Other than that drain the system, clean the plug up best you can make sure its dry then slap a load of sealant or preferably jbweld (metal epoxy halfords sell it) all over it.

Level 6 User Joined: 20 Jun 2004 Posts: 155

lol Chris what made you think I was trying to remove the manifold with coolant in the system still?! I topped the coolant up first of all before I did anything else when I went out this morning, and thats when I figured out where it was coming out from cause I could see it spraying out! I opened the bottom rad hose to drain it again before I started meddling with the manifold - honest Smile

It was at this point that I realised there was no way in hell I was getting the manifold off!

Anyway - regarding the core plugs - I've just come in from the car so I haven't checked for the core plug near the dizzy cap, but it sounds like the right kind of thing. On the manifold, the holes I found were approx 1/4 and 3/4 along the width of the manifold, and were roughly 2cm wide, and the edges were raised, if you know what I mean. Couldn't feel any bucket shaped plugs in them, unless what I was feeling was the top of the plug and not actually the top of the hole. I can't think what other holes would be on the bottom of the manifold near the head and which would leak water out when fcuked - are there any??

I drew a diagram to help you understand my confusion about what I actually found on the bottom side of the manifold. I presume that the two raised holes I could feel were actually ridges on the manifold casting as per Option A in the diagram, but your talk of bucket shaped core plugs made me think that maybe I was actually feeling the top of the core plug itself as would be the case with Option B in the diagram. Which option is actually what is there? Option B plugs would seem to be easier to remove, so I'm guessing option A is what is actually there Wink

I'd prefer to do it properly and remove the plugs if they are knacked in, but the sealant idea may end up being the only viable way to do it - if I end up having to do this am I likely to end up blocking the water jacket with sealant if I'm not careful or should whats left of the core plug contain the sealant? Is there any reason why core plugs are better than sealant?

Ahhhh bloody car and bloody lack of space to work on it! It seems a shame for a poxy core plug to finish the car off after all these years so I think I wil repair it - somehow Smile

Cheers
Alex

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

option A is right.

Gimme 5 mins

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

righty this pic shows the underside of the manifold, the coolant hose stub is missing, the core plug is the rusty round thing

this shows the entire under side of the manifold and the other shiny core plug

this shows the face, on the bottom right is where the coolant from the head enters the manifold, the coolant stub is on the other side.

Level 6 User Joined: 20 Jun 2004 Posts: 155

Ahhh excellent - thanks for the piccies. Yeh those two holes in your pics (one shiny one shitty) were the ones I could feel so I was right for a change and correctly identified something Smile

The core plugs are actually very shallow buckets aren't they? They look like they are more like frying pan or bottle cap proportions - wide and shallow. Makes it a bit clearer to me and will help me devise the best way to get the buggers out!

I think one of those thingamabobs that have a chain round two sprockets and you stick a handle on one sprocket and a screwdriver bit on the other would be useful as I could use that to screw upwards into the core plugs to get some purchase on them, but I can't remember what that tool is called so I can't go out and buy one Sad

I think putting new ones back in will probably require me to be under the car with a socket on the end of a extension bar smacking the end of it upwards - could be fun Confused

Can you push the plugs too far into the manifold or is there a lip at the bottom of the core plug holes to stop this? Don't want to knock them in so far they block the water jacket or anything.

Cheers
Alex

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

yes you can knock em in to far so make sure you don't.

see if you can poke a screwdriver into the hole then lever it out.

Level 6 User Joined: 20 Jun 2004 Posts: 155

Argggg bastard Renault!!!! Evil or Very Mad

As you can probably tell I have had the square root of bugger all luck trying to do anything regarding removing the core plug. I can't get anything to screw into it and I can't get anything under the manifold to lever it out. With retrospect I don't think I could get the new one in anyway, so I'm going to give up on that idea for the moment.

I plan to stick some JB Weld over the top of the busted one and hope that holds it for a few months. While looking on the JB Weld website, I also noticed that they sell a bunch of other (potentially) useful substances - specifically the PERM-O-SEAL product. If I can get a reasonable seal with JB Weld, and I then bung in a sachet of thie perm-o-seal stuff, I figure that that should reblock any leak if the plug weld opens up again. It might even stop the small leak in the heater matrix which comes and goes Smile

Have you guys (or maybe just Chris H if you are the only one reading this topic!) ever used this perm-o-seal stuff and know if its crap or actually works? Any tips for using JB Weld, or tips on getting the core plug as dry as possible? I have a hot air gun but I don't fancy my chances that close to the petrol lines Confused

I have already drained the coolant as best as I can, opening the bottom hose and blowing into the header tank seemed to get gallons of the stuff out. I plan to leave the car for a few days to let the core plug drip all the coolant its going to so I can wire brush it clean and then JB over the top. Might try and get some of JB's "CLEAN AND PREP" stuff, on the off chance that it works Smile

I plan that if the car needs anything major like a clutch done which requires the engine out (and probably at a garage, but there we are) I will get whoever does it to drill out the old plugs in the manifold while the lump is out since I doubt even a garage will be able to get the inlet manifold off, and it seems as easy to remove the engine with it attached anyway. I will probably be parting company with the old girl in the next 6-12 months depending on my personal life and how much work I'm doing, so as long as it lasts me that long I'll be happy. Althought it would be nice to sell her to someone in a working state when I'm done with her rather than scrapping her - I have always had an irrational hatred of scrapping cars!

Cheers
Alex

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

coolign system sealants usually successfully stop the heater workign then block up the head water ways causign localised overheating and in some cases like I have had the joy to work on dropped valve seats which wreck the engine.

clutch renewal means not engine removal btw.

Level 6 User Joined: 20 Jun 2004 Posts: 155

Ahh fair enough - I did think it sounded a bit utopian Smile

I will just JB over the core plug and see how well that goes. It should last resonably well from the looks of the JB Weld specs - its not under any mechanical stress or anything is it, and I think it should be able to handle the heat from coolant in the water jacket.

Clutch may not be an engine out job, but apparently inlet manifold core plugs are Confused

Well it is if your inlet manifold has never been taken off in 15 years...

I'll let you know how I get on with the JB when I get a chance to do it, probably this weekend.

Cheers
Alex

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

you need to use decent tools, 6 sided sockets or spanner.

Anyway the core plugs under pressure and heat, pressures not much around 1 BAR, inthe engines higher but in the hoses etc its what the caps at.

Level 6 User Joined: 20 Jun 2004 Posts: 155

I was using a fairly meaty spanner on the manifold bolts, a 3ft long heavy duty crows feet one, and even that wouldn't shift it with me or my mate I borrowed the spanner off using it. The spanner flexed a bit, but the bolts would not budge even a tiny bit. The bolts are all covered in crud and grease, so I think the only way I would get them off would be to use bolt splitters to remove the old bolts and even then I'm not sure if the big washers wouldn't be seized onto the stud threads. Either way, I would have to get the engine out to be able to get good enough access to the underneath bolts to do anything, and I have not the equipment for that.

Regarding the JB Weld stuff, are you saying that the pressure would push the weld out after a while? I don't know how good an adhesive seal it will be able to make to the manifold around the plug hole - I assume that if I use a putty knife to push it onto the actual core plug, and then smear a fair amount around the core plug hole ridge, that should hold fairly well as long as I clean it like mad before hand. Well I live in hope anyway.

Cheers
Alex

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

shoudl be fine if the areas clean enough. After all it has been used in cylinder heads etc. Trouble is gettign it clean.

Level 6 User Joined: 20 Jun 2004 Posts: 155

That was the thought that occurred to me. I reckon I can get the plug itself cleaned up with a wire brush, and maybe a fibreglass brush to roughen the surface up a bit, once I've degreased it somehow. The manifold seems a bit trickier cause its quite a grainy surface - easier to bond to I guess, but much more of an arse to clean. BTW Is the manifold steel or aluminium or some other alloy? I'm just curious as I have seen cleaner substances that are specially for certain metal types.

Chris I'm sure you have a secret top-tip for degreasing car parts like this Wink

any preferred product/homemade mixture you use?

The beast will ride again - I'm determined to bodge this sucessfully now! Very Happy

Cheers
Alex

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

its alu alloy as far as I know.

I find scrubbing with a brush and washing powder the best method tbh!

carb cleaner and the wire brush will get it pretty clean fo rthe JB to bond to.

Level 6 User Joined: 20 Jun 2004 Posts: 155

Well I been messing again having finally got some time to spare. It's a good job I've not needed the car recently for work I have to say.

I'm still trying to get the manifold clean and more importantly dry. Having (I thought) drained the coolant a few days back, today I discovered that there was still coolant just sitting in the head and manifold despite me draining it fairly thoroughly last time by disconnecting the rad hose and blowing into the header tank, so I ended up taking off the long hose that runs from the inlet manifold round the engine and down to the bottom hose joint point, at the front of the engine, and blowing into that with the expansion tank lid off. Incidentally I think that hose has been replaced in the past, which probably explains the not-too-manky inlet manifold hose stub - both ends of that hose have jubilees on instead of crappy renault clips.

Anyway, after I made myself dizzy from blowing into that pipe for about 5 minutes, I think all the coolant from the top of the engine has buggered off back down into the block and hopefully down to the bottom of the rad or that general area. I don't get much gurgling now when I blow into the coolant system, and no more coolant is coming out of the leaky core plug, so I'm guessing most of the remaining coolant is finally settled at the bottom. I'll drain that out when I do a flush before I refil.

So now I've left the thing to dry out overnight, then maybe it will be dry enough for me to mess more with it tomorrow Smile

I've also located the best tool for cleaning off most of the crap from the underside of the manifold - an old electric toothbrush head. Small enough to get under the manifold, but with a moderately good brush on the end of it. So I will be attacking the core plug area with one of those and some washing powder to start with. I bought some nice new brushes while I was in halfords, but they are massively too big, so I will have to try getting some titchy ones if the toothbrush doesn't work.

I have to say, that the underside of the inlet manifold doesn't seem to be very skanky, aside from the rusty coolant. I suppose there shouldn't really be much shite under the manifold, as its hidden from the main under bonnet airflows so it should only have residual atmospheric crap on it.

On a slightly different topic, having disassembled the carb air inlet, I noticed that the front of the carb (nearest to the block) is very oily. The frontmost hole/chamber is also spectacularly oily, so I'm assuming thats the engine bunging large quantities of oil out through the breather pipe when the desire takes it. Also I presume that having arse loads of oil in the carb is probably not going to do it much good, but I'm not sure how badly oil affects it. Does it have minimal effect on the carb performance, or should I really scrub as much out as possible? Will carb cleaner shift oil as well as dirt?

Will post again if and when I get any further!

Cheers
Alex

Forum Moderator Joined: 18 Feb 2004 Posts: 7432

carb cleaner will shift ANYTHING