Jump to content

Grogee's spannering (Puma, Maestro , Corsa & Avensis). MAESTRO MALAISE


grogee

Recommended Posts

I've commenced the cyl head swap on my Maestro before the shit weather sets in. It's supposed to be raining tomorrow and Thursday so I'll hopefully conclude Friday. 

No major worries on the removal but some of the manifold nuts were a bit loose so I've invested in some copper (cupro nickel?) high temp locking ones. 

Nice to be doing a job where it's all familiar, it was only about 9 months ago I had it all apart. 

I need to pull the valves out of the old head. I've got new valves for the new head but I need to re-use the springs, caps and collets. Then there's the fun* of checking the valve clearances using the Haynes DIY special tool. 

I'm interested to see what sort of difference the (gas flowed) head makes. It's probably pretty marginal, 10% maybe? The exhaust is noisy but surely flows pretty well. Intake is stock. 

Anyway it'll be good to button it up and have it all ship shape for Spring. Not sure if I'll tax it from March or April - I'll probably just keep an eye on the forecast and hope for no cold snaps. 

20240220_095445.jpg

20240220_095453.jpg

20240220_104706.jpg

20240220_112954.jpg

20240220_121648.jpg

Link to comment
Share on other sites

  • grogee changed the title to Grogee's spannering (Puma, Maestro , Corsa & Avensis). MAESTRO GIVES AND RECEIVES HEAD

The easy-to-use* Haynes-o-matic valve Clarence, ladies and gentlemen.

The idea is you clamp the camshaft in position then check the clearances on the lobes that aren't pushing a valve down. 

I think the book spec is 0.25-0.35 or summat like that. Mine are more like 0.35-0.40 so a bit too large. But my theory is thus:

It's a new head and new valves. No valve recession has occurred. After some miles, the valves will settle in and as they do, those clearances will shrink back towards the recommended spec. 

The other slightly more pragmatic reason for settling for this is because the bucket shims are NLA and are a stupid size (15mm diameter). I do have a few spares but they're thinner so they wouldn't improve matters. 

20240221_203802.jpg

Link to comment
Share on other sites

Head is back on. 

Obviously it wouldn't be BLARG without some unplanned aggro though:

1) The manifold studs I fitted were too short, my mistake. Probably an hour of extra faff while I removed the manifolds and changed them for slightly longer ones. 

2) Somehow I've broken the idle control valve. I was feeling smug by removing the inlet manifold and throttle body as one whole unit, then cable tieing it to the windscreen wiper to keep it out of the way. But somewhere along the line I've obviously strained the connector or perhaps knocked it. The body of the valve split from its thread which was stuck in the throttle body but fortunately it came out with a screwdriver and hammer. 

I'm not sure if I kept the original, so I need to pop to my lockup and rummage through the spares box. 

Fortunately spares are available and cheap, but it's more about the annoying wait for parts than the expense. 

20240223_091131.jpg

20240223_092932.jpg

20240223_120732.jpg

Link to comment
Share on other sites

Well. 

What the fuck is going on here? 20240223_164821.thumb.jpg.3b02f0505c71e41cf0d2b8854890d7c9.jpg

It's all bolted together so I go to fill coolant. Put in about 5 litres then went and did something else in the garage.

Then went underneath to check on some stuff and there's coolant pissing out, running down the block and off the sump. 

Immediately I assumed I'd forgotten to do up a coolant joint somewhere, but no - it's actually leaking directly from the head gasket between head and block. 

What the hell? 

I was pretty careful cleaning up the block - sanded several times, hoovered up the dust, blew it out with an airline, hoovered it again then wiped with brake clean. I'd have happily eaten dinner off it. 20240223_092911.thumb.jpg.a72694fd6833c8a3a0031f2dd4cb0371.jpg

20240223_092915.thumb.jpg.c97b099263366e9c32d42578a106d1d0.jpg

The head is also very new and very flat. The porting place said that even though the head was NOS, it wasn't flat so they skimmed it. 

I torqued the bolts according to the three step Haynes instructions: 40Nm, 80Nm, then +60° or 108Nm whichever comes first. Of course, in the spiral pattern detailed in the book. 

I can't think what's going on here. My prime suspect is the head gasket itself. The gasket has the circular inserts around the cylinders - perhaps they're too tall, or too hard, so the water jacket bit isn't sealing on the gasket. 20240223_092932.thumb.jpg.56b7868c522e919c9180f8830417c548.jpg

Just really weird that it would fail so catastrophically without even being run! 

Obviously it's all got to come apart AGAIN so that's a major pain in the ass. I do have another gasket to try so I'll just have to try that I suppose. 

Fuxache 

20240223_164847.jpg

Link to comment
Share on other sites

  • grogee changed the title to Grogee's spannering (Puma, Maestro , Corsa & Avensis). MAESTRO CATASTROPHIC OMGHGF

Not sure on the validity of the statement but I’ve read that sometimes it’s best to fill with neat water first and run the engine up to temperature before draining and refilling.

This is supposed to give the sealant on the head gasket a chance to flow/work so it’s not contaminated by the antifreeze.

Link to comment
Share on other sites

20 minutes ago, Jenson Velcro said:

Not sure on the validity of the statement but I’ve read that sometimes it’s best to fill with neat water first and run the engine up to temperature before draining and refilling.

This is supposed to give the sealant on the head gasket a chance to flow/work so it’s not contaminated by the antifreeze.

I could give it a go but blimey it's pouring out of there, it's not just a dribble. 

I've looked a bit more at head gaskets that are available for the O-series injection. The one I've used is so old there's an asbestos warning on the back of it. I don't remember when they banned the stuff from car parts but I bet it's early 90s. So every chance this 'King Seal' gasket is 30 years old. (Side note: King Seal sounds well shady). 20240223_182552.thumb.jpg.8abb0fea84a92ea7d99b17f563cd9fe1.jpg

Then there's the second one I have, a 'Tomic Limited' which has a slightly different part number:20240223_182555.thumb.jpg.d6eff43724aa0770bc3edd93c6b89615.jpg

Checking Rimmers the Rover gasket looks subtly different in the oil ways or water ways. IMG_20240223_182350.thumb.jpg.4503ae867e7f03111c0331bdc2393c69.jpg

But it's £65, and I don't need all the other gubbins supplied with it anyway. 

Not really sure what to do next. What do our resident agony mechanics think @twosmoke300 @RoverFolkUs

Link to comment
Share on other sites

9 minutes ago, grogee said:

Not really sure what to do next. What do our resident agony mechanics think @twosmoke300 @RoverFolkUs

I'll tell you what I would do - scream into a pillow and deal with it on Monday. 

Have you checked the block face with a straight edge? I've always winced at the thought of using sandpaper on a block. Unless it's cast iron, to a lesser extent. 

I'd say get a brand new head gasket. You'd think NOS parts would be fine, but in reality how has it been kept for the last 30 years? 

Folded up and put in someone's handbag ? 🤣

Link to comment
Share on other sites

5 minutes ago, RoverFolkUs said:

I'll tell you what I would do - scream into a pillow and deal with it on Monday. 

Have you checked the block face with a straight edge? I've always winced at the thought of using sandpaper on a block. Unless it's cast iron, to a lesser extent. 

I'd say get a brand new head gasket. You'd think NOS parts would be fine, but in reality how has it been kept for the last 30 years? 

Folded up and put in someone's handbag ? 🤣

Thanks, screaming into a pillow has commenced. 

Yep it's an iron block so a bit more idiot proof, maybe. I did check with my metal rule and I couldn't detect any non straightness. 

I've managed to find a genuine Rover gasket from Rimjob for a more reasonable £25, the one they have listed for MG Maestro is actually for a diesel, the twats. 

Screenshot_20240223_193124_Chrome.jpg

Link to comment
Share on other sites

3 minutes ago, Mr Pastry said:

@grogeeIf it is leaking that badly when torqued down, then something is preventing the joint from closing.  Are the dowels that you swapped from the old head possibly too long for the counterbores in the new one? 

It's a possibility I suppose. Here they are back to back. Unfortunately not the same perspective but it looks like they're sticking more proud in the new head than they did in the old. 

I knew I should have ditched them! 

Screenshot_20240223_204349_Gallery.jpg

20240220_144526.jpg

Link to comment
Share on other sites

2 hours ago, Jenson Velcro said:

Not sure on the validity of the statement but I’ve read that sometimes it’s best to fill with neat water first and run the engine up to temperature before draining and refilling.

This is supposed to give the sealant on the head gasket a chance to flow/work so it’s not contaminated by the antifreeze.

I've heard that too but I thought that was the copper head gaskets that are coated with a resin type substance that when hot helps seal. Antifreeze corrupts this. Modern composite type headgaskets not so much.

At least I hope I'm right, seeing as I've just fitted one to an a series and immediately lobbed coolant in it 🤣

@grogee. Have you tried running it up to temp? Run it up a few times, then pull the head back down? Might seal after it's seen a bit of heat maybe. If you're going to have to take its head off again and do the gasket then shit or bust maybe?

Otherwise I'm inclined to agree with @Mr Pastry and @RoverFolkUs. Either the reused dowels haven't located at full depth and holding the head clear or gasket damaged or compromised straight out the bag.

Link to comment
Share on other sites

1 hour ago, kevins said:

Also check the bolt holes are clear and the bolts are not bottoming out before they properly clamp the head.

Valve shims are the same as Lotus twin cam (also saab and TR7) and widely available.

Is an o series nut on stud or bolts? As said above it could really do with a tap running down the holes if bolts or a die running down the threads if studs. Tbf if it's pissing coolant out, a failure to torque to a book value is more likely to result in premature failure rather than instant failure to seal without even being run.

Link to comment
Share on other sites

10 hours ago, kevins said:

Also check the bolt holes are clear and the bolts are not bottoming out before they properly clamp the head.

Valve shims are the same as Lotus twin cam (also saab and TR7) and widely available.

Thanks. I found a load of shims on Rimjob's website for a TR7, are they definitely 15.5mm diameter? 

Do you happen to know if the TR7 valve spring collars and collets also fit my O-series head? (If so I can order some and get the old head cleaned up and built as a spare).

@Matty the head is bolted on. Bolts and threads are good, I cleaned them out with rag, airline etc.

I have some old bolts that I will cut the heads off to use as a guide to locate the gasket and the head. I'm going to remove the dowels and use my other gasket. 

As with all these jobs each time I have to re-do it I get quicker... And I am consoling myself with the fact that my Maestro isn't my daily driver and I'm not relying on it to get to work on Monday. 

I have a bit of time this morning and most of tomorrow assuming it's not raining, fingers crossed for completion this weekend. 

Screenshot_20240224_075531_Chrome.jpg

Screenshot_20240224_075542_Chrome.jpg

Link to comment
Share on other sites

1 hour ago, grogee said:

Thanks. I found a load of shims on Rimjob's website for a TR7, are they definitely 15.5mm diameter? 

Do you happen to know if the TR7 valve spring collars and collets also fit my O-series head? (If so I can order some and get the old head cleaned up and built as a spare).

@Matty the head is bolted on. Bolts and threads are good, I cleaned them out with rag, airline etc.

I have some old bolts that I will cut the heads off to use as a guide to locate the gasket and the head. I'm going to remove the dowels and use my other gasket. 

As with all these jobs each time I have to re-do it I get quicker... And I am consoling myself with the fact that my Maestro isn't my daily driver and I'm not relying on it to get to work on Monday. 

I have a bit of time this morning and most of tomorrow assuming it's not raining, fingers crossed for completion this weekend. 

Screenshot_20240224_075531_Chrome.jpg

Screenshot_20240224_075542_Chrome.jpg

no idea about the valve springs and caps I junked the TR7 4cyl in favour of a RV8, I did harvest the shims as spares for the elan though and they are both 15.5mm.

Link to comment
Share on other sites

Oh wow, if it's not raining it's pouring. 20240224_145735.thumb.jpg.67bb258da9dbab521c6f59ef59d8b3d5.jpg

I think I know what this is though. 

The old gasket had a rubber oval seal on the front corner for the oil way. This latest one has a copper oval seal which I suspect isn't sealing, allowing oil and water to mix. It's that corner where it's dribbling out from too. 

I've got a pukka Rover one coming so looks like I will be doing it a third time. I'm getting good now, started at 11 and finished at 3 with 1/2 hr for a sandwich. 20240224_121706.thumb.jpg.2b464639d4b04e860102b20991ec5362.jpg

Note patented Ezi-Align studs to keep the gasket and head aligned - I cut the heads off some old bolts and rounded off the ends with the grinding wheel. This time the head was fitted without the dowels, although according to my calculations there was enough space for them to sit in without fouling. 

Again - happy that this isn't my everyday transport because it's being a needy bastard. 

Link to comment
Share on other sites

21 hours ago, Matty said:

this article

Thanks, I read it and agree with most of the points made although the author sounds like a bit of a fist magnet. 

Head is off again, whipped it off this morning. Felt like a rally mechanic doing everything by muscle memory. 

It does look like the copper bit on my second gasket didn't seal, and the rubber oval seal on the previous gasket is a better solution. But concerning that it somehow found the water to mix with. 

I've given the block face another seeing to with green (production?) paper and a wooden block, so it's as clean as I can get it. 

Not sure when the Rover gasket will arrive but I've ordered some more valve shim spacers (thanks @kevins) so I'll give the Clarences another tweak while I'm waiting. It did sound a bit ticky when it ran briefly before I discovered the mayonnaise leak. 

 

20240225_105330.jpg

20240225_105338.jpg

20240225_114754.jpg

20240225_114802.jpg

Link to comment
Share on other sites

4 minutes ago, mercedade said:

Three HG replacements is getting close to @DavidB "change the gearbox on a Smart car three times" levels of rage.

Good fucking luck, man

Yes I must ask @DavidB for some rage management strategies. I seem to remember someone suggesting velcro engine mounts for him, perhaps I should do the same for my HG. 

Link to comment
Share on other sites

I always run the engine for a minute with no coolant,this melts whatever laqquer is on the gasket which creates a seal,this applies to composite ones as well which have that red bead around the edges.Then cool,retorque and fill with coolant,I then do a few hot and cold cycles,retorquing each time,before even driving it.of course if this uses stretch bolts that isnt applicable.

Link to comment
Share on other sites

2 hours ago, plasticvandan said:

I always run the engine for a minute with no coolant,this melts whatever laqquer is on the gasket which creates a seal,this applies to composite ones as well which have that red bead around the edges.Then cool,retorque and fill with coolant,I then do a few hot and cold cycles,retorquing each time,before even driving it.of course if this uses stretch bolts that isnt applicable.

I'll give it a go. I did wonder what the red line stuff was on the last one I used. 

They're not stretch bolts, just good old BL black bolt bolts. 

I am tempted to put some sealant around the waterways although I know this is strictly verboten according to all the workshop Manuels.

I've got a nasty feeling that the pukka £30 Rover gasket isn't going to work because of the location of the oil hole on the front of the block. When I looked closer at the pics it looks like it won't line up. I'll have to check when it gets here. 

I've ordered a couple of other ones just so I can get the damn thing going. Maybe I should just cut one out of copper plate... 

Link to comment
Share on other sites

Based on doing many reliant head gaskets and having them blow again,till I was told this method by an old timer,tho something obviously wrong with your gasket,coolant can and will seep through before it's got some heat into it,and the whole retorque after 500 miles thing is bonkers,which I'm sure you will find by how much the nuts turn after they have expanded and contracted a few times.

Link to comment
Share on other sites

Once more unto the breach. A small window of Dry + Daylight presented itself after the postman arrived bearing head gasket #1 of 3.

I've put it all together and fired it up, without coolant as recommended by @plasticvandan. Ran it for a minute maybe, then I've left it to heat soak.

So I don't know if it's water tight, but the good news is that it's not pissing out oil. Tomorrow I'll fill up with coolant and see how she holds. 

Fingers crossed. 🤞

Unfortunately I've managed to lose my magnet on a stick somehow, it's probably under the bonnet somewhere but a few minutes boy-looking didn't get any result. 

20240229_144728.jpg

Link to comment
Share on other sites

18 minutes ago, Noel Tidybeard said:

i think you may have misread the advice earlier- i believe you should be filling with plain water  to run it up to temp for a short while so as not to let coolant contaminate the hg before it beds in

Oh...fuck. Good news is more head gaskets on order?

Link to comment
Share on other sites

9 hours ago, Noel Tidybeard said:

i think you may have misread the advice earlier- i believe you should be filling with plain water  to run it up to temp for a short while so as not to let coolant contaminate the hg before it beds in

Nope

 

On 26/02/2024 at 18:02, plasticvandan said:

I always run the engine for a minute with no coolant,this melts whatever laqquer is on the gasket

 

Link to comment
Share on other sites

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 account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...