Time for a head gasket change

[carrera]

Not a topic title I wanted to write.

Following the loss of coolant reported here https://www.saabtechtalk.com/forum/index.php?topic=2081.msg38617#msg38617 and the fix to a leak from the wa\ter pump outlet captured here https://www.saabtechtalk.com/forum/index.php?topic=2081.msg38617#msg38617 today was when I decided to do a test run, having not seen a leak on the ramp, even though I did get it hot enough for the cooling fan to come on at 96 degrees C

With sustained revs at 3000 I did see some foaming of the coolant, along with a rise in level, but no fluid loss. A minute or so on idle & water level had dropped and the foaming was gone. Using a cheap gas detector test did not show any combustion gases

I had the OBD reader in situ & temperatures remained under control, even with  She performed faultlessly on the road, but after 15 minutes I returned to the unit to be met with a puddle of coolant on the drivers side, again. It was not coming from the water pump exit, so my conclusion is that under boost, either there is a leak allowing compression gases into the water jacket, or the head is lifting to allow the same from number 1 (if left > right)

So, I have started disassembly and parts for head gasket, gasket kit, timing belt & water pump are ordered

EXhaust & cat are off, turbo's next, before I start tackling the fuel system

It's slightly daunting as I haven't done a diesel or direct injection engine before

Thoughts, suggestions & advice welcome 

[sgould]

I did a complete engine rebuild on a diesel Mercedes many years ago.  It needed a rebore, new pistons and a crank regrind.  It was SWMBO's car donated by her father and desperatly neglected. 

The work was very similar to the petrol engines I had done.  But the cylinder pressures are so much higher the gasket joint is critical and I was advised to get the block face and the cylinder head checked for flatness and refaced if necessary. 

The clearance between the piston and the head is minimal, so there is a very small tolerance as to the amount you can remove.

My engine was "noisy"   Here's the old piston!!

[carrera]

Some fairly obvious damage there 

I'm hoping that as the leak is so marginal, there is no warping, steam erosion or other damage. Not least because I have opted to leave the block in the car.

I was unable to carry out a compression test because the access is through the glow plug hole and it needs an M9 x 1.0 adapter, which isn't in my kit & fairly expensive to acquire. I also wanted to have a look inside the combustion chamber to see if there were signs of coolant when the engine had been left overnight. Unfortunately, the hole for the glow plug tip was smaller than my endoscope camera

Somewhat reluctantly I laid spanners on the car, convincing myself that putting a timing belt & water pump on the car is something that was due & sensible preventative maintenance.

Having checked the history, I see that the belt & tensioner were done at 35k, but no sign of the water pump being done

[carrera]

Some progress

So far all the nuts & bolts have given up without snapping. The big turbo to manifold outlet bolts were looking vulnerable, and hard to access, so I decided to remove the exhaust manifold & twin turbo assembly as one item.

Pretty sure this is not what is says in WIS, but I think it's quicker, especially as i won't need to set the preloads etc on the various turbo actuators when reassembling

My next step is to get the injectors, fuel pump etc off of the top & then decide how to attack the inlet manifold

A couple of photos:

Firstly the hole where the exhaust etc used to be

Then the twin turbo assembly

[carrera]

Well, today I have been extracting injectors. All day !

I made two tools, the first one from 6mm steel. That managed to get three of them, but I was bending the forks 

The fourth one only yielded when I made another one from 10mm steel. The Saab design has a U shaped hook, and an adapter to allow connection to a slide hammer

I spoke to my MOT man who told me about a man he knows whose entire business is travelling the country extracting injectors for garages. Fortunately, I did not have to enlist his services, I got the impression that even though he's only 20 miles from me, he was not going to be charging Northern prices.

Seriously, this is not a task to be undertaken lightly.

The ZD19 / 160hp 9-5 NG use a different design of injector with the inlet on the side which means you can get some twist on the injector. The TTid has the inlet on  top so this is not possible & all the videos I found on the internet were for that design

Anyway, here's a picture showing the reluctant injector with both versions of the special tool that I made. Lump hammer, 4 1/2 lb, not slide hammer. You can jast about make out where the flats are to insert the toool. For reference it's 12.8mm across faces

[sgould]

Well done getting that out.  It does not look friendly.

I can understand why garages would use someone from outside.

[Audax]

All good garages have a guy who can drill out snapped studs, extract stuck injectors or glow plugs and insert coils into stripped threads etc.

Typically they turn up on a vintage British motorcycle that leaks oil on your workshop floor of if they are in a car it'll be from the 80's and almost certainly either a Rover SD1, Ford Sierra, Bentley Mulsanne or Jag XJS . They also tend towards drinking tea when working and cider when not working (unless they are in their workshop at home using the lathe where they will almost certainly be drinking their 10% home brew cider), they like Spitfires and have an unhealthy obsession with their collection of hand me down King Dick spanners which they own in metric, imperial and whitworth sizes.

They may be friends with Guy Martin.

[carrera]

All good garages have a guy who can drill out snapped studs, extract stuck injectors or glow plugs and insert coils into stripped threads etc.

In my garage that'll be me then 

Typically they turn up on a vintage British motorcycle that leaks oil on your workshop floor of if they are in a car it'll be from the 80's and almost certainly either a Rover SD1, Ford Sierra, Bentley Mulsanne or Jag XJS . They also tend towards drinking tea when working and cider when not working (unless they are in their workshop at home using the lathe where they will almost certainly be drinking their 10% home brew cider), they like Spitfires and have an unhealthy obsession with their collection of hand me down King Dick spanners which they own in metric, imperial and whitworth sizes.

That made me laugh, especially the bit about King Dick spanners. I remember my dad having some... oh and Whitworth and AF and metric

They may be friends with Guy Martin.

Well,  I've read a few of his books

[sgould]

I still have my Imperial and Whitworth spanners!! Also Imperial (and a few Whitworth) sockets and box spanners. 

My basic socket set will be 60 years old later this year!!  The metric sockets in it are a few years younger.

[carrera]

I still have some of the tools from my very first toolkit. Bought for my 18th birthday when I had my first engine rebuild to do. Most of my tools were bought in Sweden at Biltema. One of the few things that were cheaper, much cheaper, than the UK when I lived there

I'm metric only, except for 1/4" socket that gets occasional use for some bits

At one point I was toying with buying a BL car (can't remember what it was, but it was very low mileage). I then realised i would need to buy a whole new toolkit, so never went ahead.

Modern cars are so much more difficult to work on. Back when i was worling on VW's you could do pretty much any job with 10mm, 13mm & 17mm tools, with an occasional 19mm or 22mm for the big stuff. Whole new world with Saabs where a bottom ball joint requires 16mm & 18mm on the same fixing

[Audax]

Whole new world with Saabs where a bottom ball joint requires 16mm & 18mm on the same fixing

I always thought that was a feature, if it was 17mm on both sides and you only have one 17mm spanner you're stuck, so they put different sizes on each end of a fixing and you can remove it much more easily as you'll have the 2 spanners to work either end.

My first car was a 1986 Austin maestro, bit of a paint to work on as the same job would at different times require both metric and imperial tools.

[carrera]

In my case, I think it was a Metro I was tempted by

Anyway, back to Saabs

With the injectors out, I could continue with the removal of the head. Took my time, especially as the timing marks for the cambelt seem to be different between the ZD19, A20DTH and this A20DTR variant. I'm happy that I have made the necessary markings, but in any case I have a timing kit arriving tomorrow which sill avoid making errors. Interestingly, of all the YouTube videos I looked at, the best one was in German, (I understand a little) & I could see that he was doing the job right. It was this that confirmed that the marks I had already made were correct

Got as far as having the camshaft cover off and then hit a minor problem. I didn't have the tools I needed. Specifically a T60 bit to remove the head bolts, T55 being the biggest I have. Quite ironic considering the discussion about AF & Whitworth spanners.

Quick visit to ebay & I'll have one next day delivery on Tuesday. I suppose that will give me some time to spend on cleaning & preparation for reassembly & the timing kit & head bolts will arrive tomorrow. I couldn't see if the head bolts were TTY or reusable, so bought a set just in case.

Anyway, here's a picture. The internals look clean so far 

[carrera]

I removed the head yesterday

The good news is that there does not seem to be any erosion damage to either the head, or the block, and no warping, at least according to my steel rule

What I did notice is that the two hed bolts on the front of the head were easier to undo than the other eight

When the head was removed I saw some detritus at the front of the piston (it's inclined), which was easily removed. When I removed it with a cloth I noticed that the exhaust valves on number 1 were cleaner than those on 2-4. I have to say, the combustion chambers & pistons were very clean, certainly far cleaner than what I was expecting from a diesel

My conclusion is that the overheating from the coolant loss has allowed the head bolts to stretch allowing coolant to enter the combusion chamber when under vacuum, and exit the engine when under boost

Thoughts anyone ?

Some pictures - these were taken as removed, they're much cleaner now

[carrera]

Oh, and for all those people, like me, who thought that the A20DTR TTiD is just the same as an A20DTH except there's another turbo & a remap, it isn't anything like that simple

Best example might be the timing belt. Why would they be different, all that it does is transfer motion from the crankshaft to the camshaft, fuel pump & water pump ?

Well, the TTiD has additional guide pulleys, a different size sprocket for the injection pump, a belt that is 6mm different in length and the water pump has a metal impeller rather than plastic

If you haven't guessed, I ordered an Insignia 2.0 kit, scratched my head a bit on differences between what was on the car versus what was in the kit & then realised i needed to order a different kit, which arrived today.

The injectors, as I already mentioned are different too

It's a constant battle, picking from the Vauxhall bin for a Saab, when components might be different anyway & the Saab EPC doesn't always show parts at the lowest component level

[carrera]

This has been a long job, quite why it took me so long I don't really know, but it was probably a combination of me learning the process for removal / replacement of all the components and me taking time because I don't like breaking stuff.

When it came to restarting the car, it took quite a while to fire as the fuel system needed to fill & come up to pressure, but it did fire first time.

It sounded as if it was running on 3 and 3/4 cylinders, then I noticed diesel bubbling at the base of injector number 1. Long story short, I ended up removing all the injectors, using a tap to ensure that the thread & hole for the clamping bolt was completely clear. I then used my 1/4" drive torque wrench to tighted to 23/24nm, the upper limit on that being 25nm, which is the specification. I couldn't bring myself to apply any more torque due to concern about stripping the threads in the camshaft cover. Seems to have worked however.

The car seems to be starting better & running smoother. Perhaps that's just wishful thinking. I'll be driving home in her for the first time tonight, which will be the start of rebuilding trust in her.