The Ongoing Saga Of My Shagged Mi16 Engine

[GLPoomobile 958]

For those of you who have followed the saga, the short version of events is that it's still not fixed. For those who don't know about it, I'll provide the background below.

 

Last Dec I found it was leaking coolant at the front of the block, quite quickly, from under the front headbolt beside the engine mount. As an emergency fix, I used Holts Radweld, and that pretty much made it water tight. In all honesty, I could have probably carried on driving around like that, but I knew it was not 100% as I was getting bubbling in the header tank, and I wanted it properly fixed.

 

So last month I finally (after another 6 months laid up) took it down to Miles for what was expected to be a headgasket replacement. Upon removal, Miles found no trace of gasket failure. In fact it seemed to be in reasonable condition IIRC. There was also no sign of corrosion on the block or head.

 

After further inspection, Miles found that BOTH the head and block were not flat (this being an engine that was rebuilt by DES some 13,000 miles prior, when they did the conversion). Now at this point, I didn't need Miles to tell me that to fix the block was going to be an engine out and strip down job, which = lots of money, so I already knew in my mind that was not an option at this point. However, Miles did indeed confirm that it was going to be an expensive job, and that he believed that skimming the head would be enough to fix it (I must emphasise that Miles did not garauntee this would fix it, and it was my option as to how to procede). So we went ahead with just the head skim.

 

I picked the car up a couple of weeks ago and drove it back to London. In general it seemed fine, but it was running hotter (but I think it was running hotter when I took it down to Miles anyway). I'd already bypassed the slow speed fan resistor, as prior to taking it to Miles I had found that had failed, and in London traffic it was getting up to the 4th bar far too quickly, and the fan was running pretty much constantly, even when moving. However, aside from that it seemed to be OK.

 

I left the car for a week as I was busy, and the next time I checked it was last Friday, and found that the header was nearly empty again. Sure enough, I could see it had leaked from exactly the same place and I had a nice big brown stain down the sump. The weird thing is, even though it had been standing for a week unused, and the weather had been hot and dry, I had a massive wet patch under the engine as if the coolant loss was fresh that day, so it was must have been leaking steadily for the week.

 

Now, bearing in mind that at this point I'd pretty much accepted that the engine is a s*itter, and that I had another round trip to Edinburgh to make, I bought some K-Seal at the motor factors while I was buying more Anti Freeze. I figured it had worked before with the Radweld, so what the hell. Well the K-Seal has not 100% worked, so I don't know if the failure is worse since the head skim, or if the K-Seal is just not effective in this instance as the Radweld was (the K-Seal approval topic suggests it'll cure just about anything except Aids!). It's still weeping a small amount of coolant, but luckily not enough to significantly lower the level (I only had to top it up a small amount after 400 miles).

 

 

Continued in next post.....

Edited August 4, 2010 by GLPoomobile

[GLPoomobile 958]

I thought I better split these posts out to make this a bit more digestible

 

 

Problem number 1

 

As I said above, it is running hotter now, and this makes for very nervous use in traffic.

 

On the move, both oil and coolant temps get up very quickly, with the oil going to the 2nd mark, and the coolant to the 4th mark.

 

Cruising on a light throttle at 40-70mph will keep the coolant at just above the 3rd mark (where I presume the thermostat is rated to open), and the oil will be at about half way between the 1st and 2nd mark. Take it up 80-90mph and the coolant will creep up to mid-way between the 3rd and 4th mark, and the oil will go to the 2nd mark (note that I have no oil cooler or heat exchanger). If I then have to stop at traffic lights, or dawdle at less than 30mph, the coolant will shoot up to the 4th mark in a matter of seconds. Obviously I'm expecting it to go that high in prolonged traffic, but this happens in probably no more than a minute, even if after gentle cruising with the temp on the 3rd mark prior to stopping/slowing. At this point I've been putting the interior fans on full blow, and sometimes it'll keep it under control, but sometimes it'll keep going and only the high speed fan will keep it from rising (note that on Fri I managed to fix the slow speed resistor - dodgy connection - so I now have both speeds working). So basically I'm now completely paranoid driving it, because I'm scared it's going to overheat in traffic.

 

So suggestions please. Do you think that the cause of the temp issues is:

1 - the fact that I've partially blocked the waterways with the Radweld and K-Seal, or

2 - the fact that the coolant is being pressurised, or

3 - both of the above?

 

The only thing I can think to do in the meantime is

1 - Drain the coolant, remove the rad and thermostat and flush the engine and rad through thoroughly

2 - Fit a lower rated thermostat to keep temps a little lower when on the move, and hopefully give a headstart on the cooling before hitting traffic

3 - Refit the OE top hose (got silicone now) so I can ensure the system is bled using the bleed nipple, just in case air locks are an issue

4 - Use a Water Wetter product

5 - Ensure that any blanking plates on the top and bottom grills are removed

6 - Wire in a fan switch so I can get the high speed fans on when I want, which will at least help relieve paranoia

 

I realise that flushing the system to remove the K-Seal and Radweld will mean it'll leak again, but I have to see if it makes any difference to the temps.

 

Anyone else got any bright ideas?

 

Problem 2 in next post....

Edited August 4, 2010 by GLPoomobile

[omega 82]

think you have all the possible solutions covered

good luck.

[GLPoomobile 958]

Problem number 2

 

The next problem is with oil pressure, or lack thereof!

 

Historically I've always found that the hot oil pressure is quite low on the OE gauge at idle (1k rpm). I've noticed this getting worse over time. I don't have a working warning light, as I've never been able to get the switch to work (yes, I'm ashamed that I still have not resolved it after all this time ), but the engine has not died......yet

 

I'm now finding that with the engine up to temp it'll drop right down to the first bar (as in minimum) at idle. Not quite sitting ON the first bar, but as close as damnit. I've even noticed it's got worse over this weekend in Edinburgh, as at the end of the journey up it was only sitting that low when the oil temp was on the 2nd bar (and when the temp was between the 1st and 2nd bar the pressure would sit fractionally higher than minimum), but by the time I got back to London on Mon night it was sitting at minimum even with the oil temps lower than the 2nd bar (it's obviously fine when cold). When hot, the pressure will max at about half on the gauge.

 

I'm half and half as to what the problem is here (aside from the obvious - that engine wear could be the main problem). On the one hand I'm wondering if coolant in the oil (yes, I do have mayo in the cap) is thinning it out. On the other hand I'm wondering if it's simply a product of the fact it's running so hot now.

 

I can't see any water on the dip stick. The oil was changed prior to taking it to Miles (not sure if he did another oil change while it was there), and it's not using much coolant (most of which escapes out the front of the block). How much coolant would be neeeded to thin the oil out? I'm guessing very little.

 

I'm not convinced this is just a result of the temps, as it's not unusual to have the coolant on the 4th bar and oil on the 2nd, and it's never resulted in pressure this low before.

 

So my plan of action at the moment is:

1 - Do another oil change this weekend and see if improves (which will confirm if coolant in the oil is thinning it out)

2 - Knock the idle speed up a smidge to 'mask' the problem at idle

3 - Temp connect my TIM pressure gauage and see what that shows

4 - Take it to a garage and get them to check it on a proper mechanical gauge

5 - If definately low, try using a thicker rated oil

 

Any other ideas?

 

I can't fix either problem in the short-mid term, so I have to simply try and alleviate them as best as I can (it won't be a daily driver anyway).

Edited August 4, 2010 by GLPoomobile

[mfield 20]

4 - Use a Water Wetter product

 

I've been sucked into that in the past, yes it works but while there is a clear problem you're likely to be draining and refilling the water system a few times before a fix is found. Would just be a waste, besides it's just masking the problem not fixing it.

 

The amount of time it's spent sitting around you've probably got sludge in the bottom of the block and the rad ? What's the condition of the rad ? I once changed from a shagged old one ( that looked ok tbh ) to a new rad and the difference was massive.

[Tom Fenton 1,525]

Ref problem 1- on my turbo car I thought it was on the hot side according to the dash gauge. However the 4th line only actually equates to about 85 deg C according to the ECU when I plugged it in. So really, is it actually running hot, or is it just the gauge fooling you into thinking it is running hot?

Also the speed at which the temp goes up and down- this is a good sign to me- my car does this as I cleaned the liner faces and block face to make them spotless- to help the heat transfer out of the metal into the coolant.

 

Ref problem 2- on my Mi track day car I was worried about oil pressure again, according to the standard gauge. After installing a SPA digital gauge it again shows up the weakness of the standard instrument. Sat just above the 1st line on the oil pressure can be anywhere between about 20 and 30 psi. Immediately after a 9 min ring lap, with everything stinking hot, the gauge showed on the 1st line at idle with the SPA gauge showing 20psi.

[GLPoomobile 958]

Tom

 

 

You raise 2 good points there, and I have obviously accepted that the gauges are guess-o-meters . But despite this, it's the change in the readings, rather than the readings them selves that worries me. The fact that the oil pressure is getting lower now, and the engine is (seemingly) running hotter is what makes me paranoid.

 

The 4th bar on the coolant temp gauge is just before the fan cuts in, so it's not too hot, and I don't have a prblem with that. It's the fact that the temps shoot up really quickly now, and are only just brought back in check by the high speed fan. Put it this way, I wouldn't feel comfortable sitting in a motorway traffic jam. Plus the fact the temps increase rapidly from the briefest of full throttle blats.

 

Basically I think it shows that the system is struggling to keep temps under control. So really I'm after an educated guess as to whether that points to the Radweld/K-Seal sludging up the waterways, or if it's more likely to do with the system being pressurised. I've no idea how much of an impact the extra pressure in the system would have on temps

 

mfield - rad is in good condition, but I have no issue with replacing it if does the trick.

[kyepan 291]

put a new engine in.

 

sounds like a simpler plan all round. Baz has several for sale IIRC

[GLPoomobile 958]

Long term, that probably will be the plan. Short term, money is an issue and I'm moving back to edinburgh at the end of the month, and will then need to find workshop space to do it. So the priority for now is to

 

a} confirm what's actually going on with temps and pressure

b} work out how I can reduce the problems (if they are problems) and make it last as long as possible

 

If the engine s*it's itself before it's replaced, then so be it.

Edited August 4, 2010 by GLPoomobile

[dcc 855]

I remember a mate of mine who had a mi16 in his 205 said that he had uneven faces between head and block, so he decided to just put 2 headgaskets on, he reckons it sorted the problems he had, similar to yours, but he lacked power with the reduced CR. it was a temp fix.

[gowmonster 2]

would it not be better/cheaper/quicker to source a decent engine from someone off here that is doing a gti6/mi16 conversion?

[GLPoomobile 958]

Do you mean using a cheap 8v that someone is flogging to do a 16v conversion?

 

The thought of going back to 1.6 8v has crossed my mind, but I couldn't go back to Jetronic.

 

In theory, swapping back to standard 8v would be the cheapest route. The best route would be to stay 16v and maybe end up with something even lairier. The quickest route....well there is no quickest route at the moment for the reasons mentioned in a previous post. Once I get settled back in Edinburgh, get a 2nd car and find some work space then I can consider the options. That probably takes me up in to early next year, so my priority between then and now is to either alleviate or mask these issues. The consequences being that it'll either survive until I come up with a proper plan, or it'll die. The latter I no longer consider any great loss to be perfectly frank.

[Masekwm 2]

Perhaps change the rad, my old mi ran warm but with the replacement £30 rad it behaved much better.

[harryskid 193]

What is it with you chaps and this f**king k seal?

[GLPoomobile 958]

If you have a better solution to prevent 5 litres of coolant loss just hours prior to setting off on 900 mile round trip, I'd love to hear it

 

See that's what I love about this forum - every problem, no matter how big, is made in to something trivial. I love the wealth of technical knowledge on here, but it would be nice if sometimes people could remember that not every member has a workshop, a full tool collection, all the experience necessary to do every job, or the time and money.

 

Bodge may be a dirty word, but it exists through necessity.

[SurGie 54]

Genius happens through sheer effort even if than means loads of bodges happen along the way. Good luck with it all GLP.

[mattmk1 0]

Iv just had a quick skim read so bare with me as i maybe missing the point. But i dont think you have any major issues with the engine bar the leak.

 

Does it miss-fire? Take the cap off the expansion tank and start the engine, place your hand over the expansion tank neck (so your hand seals)? Can you feel any pressure building? If not your headgasket should be fine. Most old engine blocks, especially alloy ones arent 100% true straight and flat, you torque the head down in sequence to help counter act this problem, so dont worry about this, as it may be something thats praying on your mind and avoiding you looking for the smaller solutions.

 

The leak, is the block damaged? IS the cylinder head bolt thread fecked or has the block gone porous through corrosion? Both cause leaks, k-seal sorts problem 2, engine strip and rebuild sorts 1.

 

No dramas with using k seal, i think people forget that products are developed and tested to the extreme before being unleashed on the public. If they werent and k seal blocked water pipes or some of the other strange internet stories were true, the manufacturers would be sued. A lot. So dont worry about using it, if it fixes a crack in the block or porous block then happy days.

 

Getting hot? Checked the thermostat? Is heater matrix blocked? How is the cooling pipes ran on your engine? Sure you didnt get an air lock when you filled the coolant up? How old is your rad?

 

You said the coolant on the floor was red? Was this because your using pink antifreeze or is it rust? If rust, suggests your blocks corroding so coolant flush it and then use high quality anti freeze. Halfords advanced stuff is pretty good.

 

Oil pressure? Not a problem. Always always sits on the first mark at hot idle, only worry if the needle doesnt respond to engine revs. You can get the needle to sit higher by using different oil pump drive cogs etc but then you just force oil out of every ageing seal when you put your boot down.

 

Different oil will place the needle differently aswell, use a 5 50w fully synthetic to bump it up a little, or shell helix is very good. MAyo in the cap? Again, its always there. Condensation from the crap beather system on these engines, so ignore it.

 

Hope that helps.

[GLPoomobile 958]

Matt - excellent, thoughtful, and helpful reply. Thank you very much I probably am making a mountain out of a mole hill as per usual and there is perhaps not much wrong, but I intend to find out over time, so I'll keep updating this topic as I progress. I've repsonded to your comments below in red....

 

Does it miss-fire?

Nope

 

Take the cap off the expansion tank and start the engine, place your hand over the expansion tank neck (so your hand seals)? Can you feel any pressure building? If not your headgasket should be fine.

I haven't tested it since it came back from Miles, but I'll give it a try.

 

The leak, is the block damaged? IS the cylinder head bolt thread fecked or has the block gone porous through corrosion? Both cause leaks, k-seal sorts problem 2, engine strip and rebuild sorts 1.

Miles couldn't find any damage or corrosion. The head was pressure tested too.

 

Getting hot? Checked the thermostat? Is heater matrix blocked? How is the cooling pipes ran on your engine? Sure you didnt get an air lock when you filled the coolant up? How old is your rad?

It's not that it's getting too hot, as I've not let it get that far, it's the speed with which the temps increase now and the difficulty it has in bringing temps back down that worries me. Haven't checked termostat yet, but will be replacing it anyway. Matrix is fine. I have the standard Mi16 cooling route, except Miles has now bypassed the TB. Likewise it was Miles that filled the coolant and I'm sure he's capable of bleeding it correctly . Don't know the age of the rad but externally it looks fine. I will flush it out and then replace it if still having issues.

 

You said the coolant on the floor was red? Was this because your using pink antifreeze or is it rust? If rust, suggests your blocks corroding so coolant flush it and then use high quality anti freeze. Halfords advanced stuff is pretty good.

I don't remember saying it was red

 

Oil pressure? Not a problem. Always always sits on the first mark at hot idle, only worry if the needle doesnt respond to engine revs. You can get the needle to sit higher by using different oil pump drive cogs etc but then you just force oil out of every ageing seal when you put your boot down.

As I said, it's not the reading that worries me (although it's sensible to be concerned) but the fact that hot oil pressure has been dropping since I bought the car. Responds fine to throttle though.

 

Different oil will place the needle differently aswell, use a 5 50w fully synthetic to bump it up a little, or shell helix is very good.

Once I've established the TRUE pressure reading, I will be trying a 50W oil if it is indeed low.

 

MAyo in the cap? Again, its always there. Condensation from the crap beather system on these engines, so ignore it.

Yeah, I'm aware of the condensation issue these breather systems have. But, this car has not been used for any short journeys since the work. It's just done a long journey from Miles' (twixt Salisbury and Southampton) back to London, and the round trip to Edinburgh and back. So it really should be clear under those conditions.

 

 

One other question - before I took it to Miles if I ran the engine with the cap off I could see lots of very fine bubbles coming up in the water, which I understood to mean that the system was being pressurised. But now that Miles has bypassed the TB, all I can see is a constant flow of coolant coming out of the return hose (where it enters on the top right of the tank) in to the tank. So I can't if there is any bubbling, as all I can see is that steady stream of coolant rushing back in through the top. Is that normal? I feel like a div even asking the question

[JimLad 1]

Did you speak to the people who rebuilt the engine or is it well out of their warranty? Seems a bit poor that it only lasted 13,000 miles afer a rebuild which no doubt didn't come cheap.

[Miles 331 1 Cars]

Just a note about the stat while I remember, As you;ve got the 405 set up you need the 405 stat, the 205 works but not quite right as it's not 2 stage

 

DES built the engine a while back I believe

[gowmonster 2]

what i meant was, that if your knackered engine is standard, then perhaps someone off here that is doing a gti6/mi16 conversion, would sell you their good old engine.

[harryskid 193]

If you have a better solution to prevent 5 litres of coolant loss just hours prior to setting off on 900 mile round trip, I'd love to hear it

 

See that's what I love about this forum - every problem, no matter how big, is made in to something trivial. I love the wealth of technical knowledge on here, but it would be nice if sometimes people could remember that not every member has a workshop, a full tool collection, all the experience necessary to do every job, or the time and money.

 

Bodge may be a dirty word, but it exists through necessity.

 

Surely if you knew you had a 5 ltr coolant leak why put the engine at risk with a 900 mile trip. Not being rude but to me the problem should have been sorted first as now its looks like its going to cost a whole lot more. Ive got a sick vts engine and last Sat i was meant to do a rally, common sense told me it wasn't going to happen. It cost me a couple hundred quid in lost entry fee but at least i didn't hurt the engine further. I'am sorry for your problems but workshop, tools, experience, time and money are not really an excuse when you knew you had a problem!

[GLPoomobile 958]

Frankly, I find that reply patronising and offensive. It's very easy to be holier than thou when you don't know somebody's circumstances.

 

I suggest you refrain from further input on this topic unless you have something constructive to add, as you are going to really get my back up

[large 33]

Crap post

Edited August 6, 2010 by large

[kyepan 291]

Paul and I will have done two engine swaps in two weekends by the end of this weekend, I still suggest this as the best course of action, for minimum hassle. Anything can be done by the road side, engine cranes cost fifty quid to hire for the weekend. Job done. you need six foot of space in front of the car.

 

Also, without reading between the lines of some of the longer posts (sorry i'm busy at work atm and don't have time to wade through your very well written diatribe) do you actually know where the coolant is going?

 

1) its getting thrown down the exhaust

2) its leaking but onto something hot so you can't see it drip

3) its leaking, drip drip drip

 

short answer please

 

J

Edited August 6, 2010 by kyepan