| Author |
 Topic  |
|
| |
Current Topic Rating:  | Join the Forum to Rate this Topic at: www.VNCommodore.com Support Forums
|
|
|
Mr Persistant
P Plater
72 Posts
 |
 Posted - 01 Dec 2010 : 8:49:08 PM
|
How bad an idea is this? They are Bovac brand. I bought them on Ebay, then had severe buyers remorse. I'm probably going to install them when they arrive, despite my better judgement.
I'm going to inspect the head surface with a metal straight ruler, but if I don't see any sign of surface imperfection...I'm not even gonna get them machined, much less reconditioned..  It's like $750 for a pair or reconditioned heads...
I am gonna buy some new head bolts, though. What? Do you think I'm THAT bodgy that I wouldn't? 
|
|
Report to Moderator |
|
|
Mechknight73
National Driver
1001 Posts
|
Posted - 01 Dec 2010 : 10:06:17 PM
|
| If you're wrong, it means you have to do the whole job over again. Best to spend a little more and get the head machined if it needs it, rather than having to spend a lot on all the other gaskets associated with a head rebuild twice; valley cover, exhaust gaskets, rocker covers and so on |
Edited by - Mechknight73 on 01 Dec 2010 10:07:05 PM |
Report to Moderator  |
|
|
Mr Persistant
P Plater
72 Posts
|
Posted - 01 Dec 2010 : 10:41:46 PM
|
Well, I did say I would examine it with a steel straight edge (& feeler gauges). If it doesn't look dead smooth and flat, rest assured, I WILL get it machined. I think I already know there's gonna be at least minor pitting, but I have to be optimistic, right?
I checked, and it's actually pretty reasonable just to get the headgasket surface ground...waaay less than full reco job. I'm not sure how much swarf and iron filings would end up inside the valve spring area, though.  Dunno if I could be sure of getting all such material out of there before installation.
I'm still worried about this cheapo gasket set though. I'm hoping that even mediocre gaskets can contain the power & might of the VN V6. Or I will crack and buy an ACL set like I shoulda in the first place...
The best part? I'm prolly gonna drive it as is for several weeks before doing this - probably. Hope I the gasses don't gouge a groove in any surface in that time. Engine oil seems uncontaminated at least, for now. |
| Report to Moderator |
|
|
Mechknight73
National Driver
1001 Posts
|
Posted - 02 Dec 2010 : 5:40:42 PM
|
Having seen many engines die from blown head gaskets, it surprises me that an iron head will do this, unless you retrofitted your VN with an Ecotec. Until the Ecotec, all Commodore V6s were iron heads. Iron heads generally don't warp when they overheat; if anything they crack, and you have to get them super hot to do it. Alloy heads will warp like a banana if you get them too hot, and depending on how hot, will readily mix oil and water into a sickly mess.
There is a way of checking the severity of a blown head gasket. The first is gauging just how much "gas" is blowing through the cooling system. Take off the radiator cap when cold, and let it get to operating temperature. Once the thermostat is open, watch to see how much it bubbles. Keep filling it up and see if it keeps bubbling consistently. S1s, if down on water, will bubble for a while when you fill them up, then stop, if everything else is ok. A crook one will keep bubbling like a stewpot on high heat. S2s will do this a bit, but you have to open the bleed valve as well.
When the head is being "planed" there is no pressure on any of the valve stems, so all the valves will be shut. All you'd have to do is clean up around the valves, to get rid of any loose filings |
Edited by - Mechknight73 on 02 Dec 2010 5:42:23 PM |
| Report to Moderator |
|
|
Mr Persistant
P Plater
72 Posts
|
Posted - 02 Dec 2010 : 9:13:33 PM
|
Yes, I realise the valves would be closed whilst the head was getting ground - I just think there's a high risk of some sort of filings/crap ending up in the exposed rocker area at some point during the time the heads are being worked on. My guess is they don't often do only a resurface on a head. I don't know how careful they can/will be regarding that.
I agree with you re iron heads. I was/am really hoping that a short, iron head with only a moderate leak (on old, original gaskets) is not significantly out of whack in any dimension. I didn't realise before checking the internet a bit that it's actually pretty common for these motors to blow headgaskets, cos I thought that was one of their strengths. 
To be fair though, I believe my slowly emerging gasket issues (like most others) probably stem from an overheated engine many years ago (holed radiator that 'someone' drove until until they got off the freeway to a shopping centre  ). At the time, you think you got away with it...but it catches up with eventually. The potential for cracking worries me a little though - they can't check this is they only do a resurface.
But like you say, I'm counting on the all cast iron engine and short V6 heads to be much tougher than an alloy straight 6. Shoot, I was hoping to get 500k kms out of this engine without major work.  Until a few days ago, I'd never had to so much as take the tappet covers off. Original w-pump. Not too shaby for 280k kms. |
| Report to Moderator |
|
|
Mr Persistant
P Plater
72 Posts
|
Posted - 03 Dec 2010 : 4:11:26 PM
|
"There is a way of checking the severity of a blown head gasket. The first is gauging just how much "gas" is blowing..."
I don't know about bubbling on mine. What I do know is I have a new radiator cap on a near new radiator on an engine at normal operating temperature that can't stop a steady trickle out the very top of the radiator cap. There's green spray around the rad cap and on the plastic guard/spoiler thing at the base of the radiator when I get home.
I don't really know why it's not simply blowing out the 'other' screw-on CAP on the opaque plastic coolant bottle on the driver's side...because that is where the hose comes from to feed the ordinary, non-pressurised overflow bottle. I've had to replace the internals of that cap before due to it NOT holding pressure, so I can't imagine it holding TOO MUCH pressure now.
I guess I should check it. Theoretically, no matter how much pressure builds up...it should be spewing out THAT cap's overflow tube and feeding into the overflow bottle. The 'overflow tube' from the radiator fill-neck only feeds back to that original plastic, full-pressure bottle. Confused? It's because I think the S1 *never had* a cap on the radiator orginally, AFAIK, but of course you can't buy a radiator without a filler neck for some time now.
So I'm kinda running a combination of both, which should not be a problem, and hasn't been a problem, until now
..also, there is significnat 'brown cream' in that full-pressure plastic bottle with the cap. I don't even know if some of that muck isn't clogging up the pressure release valve in that cap. Seems unlikely ...
So, all things considered it's hard to to not come to the conclusion that the head gasket has been slowly leaking a little bit for some time and is now approaching critical point and getting worse. It took me a little while to accept it. |
| Report to Moderator |
|
|
Mechknight73
National Driver
1001 Posts
|
Posted - 03 Dec 2010 : 10:43:34 PM
|
This is true, S1s are only meant to have a "radiator cap" on their header tank, the plastic bottle mounted above the battery on the strut tower. There's a chemical test to tell you for sure whether the head gasket is shot, but it's genera;;y only found in workshops.
That brown muck shouldn't clog up the pressure release valve on the cap; mine used to have that kind of gunk in the tank, and it made no difference to it venting when it got hot. I never "fried" the engine, but it did get a bit hot when the radiator fan started playing funny buggers. It still vented with all the subtlety of a runaway locomotive
|
| Report to Moderator |
|
|
Mr Persistant
P Plater
72 Posts
|
Posted - 04 Dec 2010 : 4:13:21 PM
|
Just for the benefit of us hard-core, budget-oriented, VN drivers, I phoned the Australian seller of those Bovac brand gaskets ... and they said they run a workshop in semi-rural Victoria and have been using these gaskets with no comebacks for 6-7 years. Their advice was there would be no problems, as long as I "wasn't using a supercharger". That's good enough for me.  |
| Report to Moderator |
|
|
Mr Persistant
P Plater
72 Posts
|
Posted - 22 Dec 2010 : 08:41:48 AM
|
Does anyone know where to find the torque specs for VN V6 headbolts and intake manifold bolts? Link anyone? Manual?
I spent some time looking on various forums - a USA site for Buick 3800 and a little info from justcommodores.com - and think I found that headbolts should be about 80Nm (I saved it on my computer at home somewhere)...and I think I read the intake bolts should be around 15Nm ???? which seems *very* low for the latter..kind of expected double that at least for intake manifold, although their biggest task really is only to seal 20PSI of water at the ends of the manifold.
I have an old, but rarely used (and never dropped ) Norbar torque wrench that goes from 0-100Nm, so I'm planning to use that. It's the 'twist-grip style' to set the clicker. Man, it's a long time since I used that.
I have all the parts ready to do it. Just have to wait until last week of January for the time. Will probably get heads resurfaced > You talked me into that, Mechknight, thankyou. Don't know what I was thinking. 
I'm certain this job needs doing and am not spending $90 to get a CO sniffer test done on the radiator > still spitting small amounts of coolant out the radiator for no apparent reason. |
| Report to Moderator |
|
|
Mechknight73
National Driver
1001 Posts
|
Posted - 22 Dec 2010 : 11:46:46 AM
|
Read up in the manual the torque specs for the heads and manifolds. They are as follows:
Heads, step one-34Nm. Step two, turn the bolts 90 degrees. Step three, 81Nm.
Exhaust manifold studs- 40-60Nm. The nuts are 20-27Nm.
Evidently the manual agrees about the low torque on the inlet manifold bolts too, 8-12 Nm. Strangely it lists the torque on the inlet plenum at the back of the manifold as 10-14Nm
This is all what I'm quoting from the service manual.
While the heads are off, go through the entire cooling system with a fine tooth comb. If anything looks even slightly suss, chuck it or recondition it. Also, one of the best kinds of coolant on the market is the genuine Toyota coolant. It's not the cheapest, but it works really well, and helps to do the other 50% of the work coolant is supposed to do; inhibit corrosion. Don't worry about the "raspberry cordial" colour, it's really good stuff. |
Edited by - Mechknight73 on 22 Dec 2010 11:50:39 AM |
| Report to Moderator |
|
|
Mr Persistant
P Plater
72 Posts
|
Posted - 23 Dec 2010 : 08:59:47 AM
|
Thanks Mechknight. Three step tightening procedure. My memory was a little rusty on that one. Good to get confirmation on those intake manifold bolts. Three different information sources can't be wrong. I don't think I'll be taking the exhaust manifold studs out, though. They can machine the head with them in? I will ask them on the phone before I take them in. Was quoted $100 to skim both heads a few weeks ago.
Re the coolant > already bought some at Repco with the other stuff. I *think* it'll be okay..
I got Tectalloy brand, as usual, which I thought was supposed to be the GMH recommended stuff for Holden V6 cast iron motors. It seemed cheaper this time at around $20, and it came in a smallish 1L bottle or so, rather than the 4L container you used to have to buy it in...AND I read the bottle and it does NOT cover temps below 0 Celsius...so is not a proper anti-freeze in the true sense of the word, not that it gets that cold in Brisbane. But still, it makes me a little suspicious of how good it actually is.
I'm pretty sure it meets the requirements of the VN V6 as I can't see Tectalloy ruining their name with a dodgy product. I'm just a little confused why it doesn't say it protects below freezing point... I'm guessing they cheaped out a little on the glycol...I might look into it some more.
Re the rest of the system...aghh, I can't help but think of the original heater core I did NOT replace when I replaced the evaporator. Yes, I know, that was stupid.  It looked okay...
The waterpump seems fine, think I'll just leave it unless someone can tell me it's on it's last legs at 285K kms. The radiator is less than 6 mths old. No bad looking hoses. It's kind of just a "gaskets and deck the heads" job.
Total cost for job is not too bad (about $300 incl machining), and if anything else should go wrong later, it's not like there's anything that would be any easier to do now with the heads off. |
| Report to Moderator |
|
|
Mechknight73
National Driver
1001 Posts
|
Posted - 23 Dec 2010 : 11:00:13 AM
|
What they mean when they say it protects below freezing point, is that it lowers the freezing point of the coolant. If your coolant did freeze, it would expand and break the weak points of the cooling system, such as the radiator.
The main thing to check on the water pump is the bearing. With the pulley attached, see if you can rock it from side to side, just as you would a front wheel bearing. If there's no lateral play in it, no problem.
The head exhaust stud don't need to be removed for machining the heads; I've seen hundreds of heads go to the machine shop missing only yhe rocker and/or cam gear. All that matters in this case is that the gasket surface is returned to its original condition. I just put in all the specs in case one of them happened to somehow come loose
The heater core is a pain because of the amount of stuff you have to dismantle to get at it. It's not a job I'd do unless I HAD to. If you smell glycol in the cabin with the heater on, then you know you'll have to do something about it. |
| Report to Moderator |
|
|
Mr Persistant
P Plater
72 Posts
|
Posted - 24 Dec 2010 : 07:46:29 AM
|
Thanks. I know about the freezing point and boiling point stuff. What I was sold is this:
http://www.tectaloy.com/page25.html
...which is probably good corrosion protection, but it explicitly says it offer NO ANTI-Freeze properties...as in it would turn to ice and crack the block should I want to drive to the Snowy Mtns next July for a skiing holiday. It is corrosion protection only.
If it can't stop freezing, I suspect it doesn't raise the boiling point either. And I have been told the GMH V6 has hot spots in the head that make this a good idea to have, or else you can get steam pockets...which could cause cracking and I've also heard of it causing w/pump problems. I think that's part of the reason Tectaloy made a coolant just for the Aussie GMH cast iron V6, for all years from 1988-2004.
What I wanted is what I have been using for years, this:
http://www.tectaloy.com/page33.html
EDIT: OK, I just read the info in the last link there > the VPlus for Commodores was replaced a year ago by this the "Antifree-Antiboil" product:
http://www.tectaloy.com/page26.html |
Edited by - Mr Persistant on 24 Dec 2010 08:36:46 AM |
| Report to Moderator |
|
|
Mechknight73
National Driver
1001 Posts
|
Posted - 24 Dec 2010 : 2:18:56 PM
|
It's funny, because all the VN-S Lexcens all use the stock Toyota coolant; I know this because I worked for two Toyota dealers. Unless a customer specified it, they all used the distinctive red genuine Toyota stuff, and it seems to be superior to anything else I've seen bar racing coolant.
I'm not doubting that Tectaloy made one specific for the VN V6, but Toyota are the first ones to call a recall if there's the slightest whiff of a major problem. No Lexcens I've ever seen in my years (1996-1999) ever came in for things like blown head gaskets. |
| Report to Moderator |
|
|
Mr Persistant
P Plater
72 Posts
|
Posted - 25 Dec 2010 : 08:47:53 AM
|
I think most car nuts these days agree that it's probably safest to stick with manufacturer brand coolant.
I'm annoyed I got sold the lower level Tectaloy product when I knew what I was asking for and wanted and got talked down to this cheap crap. They're going to switch it for me with a full-spec Repco brand. I have no idea what's in that.
I mean, who wants that half-assed stuff? >> People selling the car in 12mths time, I assume. It's not worth the time of going and getting it from the shop and installing it properly into the cooling system.
Frankly, I'm concerned Repco increasingly is on a par with Supercheap or Ebay. Not quite, but that's where they're heading. Inevitable perhaps. Just makes it harder to know what brand to get and where to get it when you want something decent.
Oh, and Merry Xmas, MechKnight. And Happy New Year. I got a big year lined up for myself...and you're moving I think I read. Good luck! |
Edited by - Mr Persistant on 25 Dec 2010 08:51:12 AM |
| Report to Moderator |
|
|
Mr Persistant
P Plater
72 Posts
|
Posted - 26 Jan 2011 : 6:50:17 PM
|
Getting closer to doing this, when it occured to me I didn't have rocker arm bolt torque specs - which I found online: 15Nm + 90 degrees.
So, it Looks like I need to buy a tool to measure as I turn the breaker bar that 90 degrees. What do you even call that? I looked on Ebay for something cheap - no joy. I've never used one even.
AND, the rocker arm bolts are like the headbolts - non-reusable, which I had not realised. There are numerous stories of them coming loose or breaking online, which also explains some of the other rocker gear issues I saw years ago. Couldn't find the bolts on Ebay either. Might be a Repco or GMH purchase?
There's a bit more to doing this right than I first anticipated. I'll get there yet. Appreciate any suggestions. |
| Report to Moderator |
|
|
dryVN
Fully Licenced
228 Posts
|
Posted - 26 Jan 2011 : 7:28:40 PM
|
| 15 nm + 1/4 turn which close enough , your eye would be ok for. |
| Report to Moderator |
|
|
voodoo92
Fully Licenced
150 Posts
|
Posted - 26 Jan 2011 : 7:37:28 PM
|
| wow thats upprising to hear about having to use new bolts on the head and rockers... would never have thought about that. haha. and i would have hought for the 90 degrees it would be an estimate, but i suppose you can never be to suer with your baby :) |
Bassist by day, VN nut by night |
| Report to Moderator |
|
|
dryVN
Fully Licenced
228 Posts
|
Posted - 26 Jan 2011 : 7:41:39 PM
|
also any thing long with a right angle can be positioned next to the breaker bar for greater accuracy.
I have done older car's , never had the need to crack the heads on a VN , would be an interesting process and if you have any pic's could you post em up for future site reference please Mr Persistant. cheers |
| Report to Moderator |
|
|
Mr Persistant
P Plater
72 Posts
|
Posted - 26 Jan 2011 : 8:10:26 PM
|
| I'll try remember to take some pics and figure out where to host them. Might help feel less alone doing it. Don't really want to do this right now, but it is consistently pushing out a small amount of water, (spray marks around rad cap) which it never used to, and there is only one explanation for it that i can see. I have most the parts now, but I may leave it a little while yet.. |
| Report to Moderator |
|
|
dryVN
Fully Licenced
228 Posts
|
Posted - 26 Jan 2011 : 8:17:56 PM
|
| Cheers mate , Best of luck when it's a goer |
| Report to Moderator |
|
| |
Topic |
|
Topic Locked
