So apparently I'm going to have a Saab project

Finally something to report. As mentioned earlier, I always planned to add some gauges to this car. The first attempt, with an 80s electronic combo gauge, was an abject failure. After that, I took a while deciding whether to go with mechanical or electronic gauges; in the end I couldn't get over my dislike of pressurized oil being pumped into the cabin, so electronic it was to be.

From there I had a choice: spend real money for real gauges, or roll the dice on cheap Chinese units from Amazon. Cheap car, cheap gauges. I found a triple set with sending units included for somewhere around $25. As a bonus (to me) they were calibrated in metric units, something I've always preferred in European cars.

A lot of the work was done, as I had already run the wires into the engine bay. The main issues were feeding a signal to the temp gauge (more on that in a minute) and figuring out how and where to mount the plate (and doing whatever additional wiring that entailed). The 900 has a DIN slot down in the center stack, and I figured I'd either put the gauges there, or move the radio down since I rarely use it and put the gauges up higher in the dash. The latter was certainly more useful, but also entailed more work. It being cold in the garage this time of year, less work won. As it turns out, this was a better decision than I expected.

That decided, the first thing I did was figure out where I was going to get power for the gauges and the lighting, and make up the harnesses. I pulled the light circuit from the courtesy light in the ashtray, and the main power and ground from the cigarette lighter, both very close. I used spade connectors to make removal easy should it be necessary.

That done, I installed the new oil pressure sender (I already had a T-fitting in there from the last attempt) and wired it up. That left the temp sender. I measured a nearby heater hose as having a 22mm ID, which then led me to Amazon to find an adapter fitting (for motorcycles, as it turns out). The only issue with this is that the sender needs to be grounded, so I had to add a wire to accomplish that. I thought about tapping it, but the walls are fairly thin and I didn't want an additional potential leak source. Instead, I found a ring terminal that slipped under the sender, then cut a piece of fuel hose to act as a spacer and put some pressure on the terminal when the sender was tightened into the adpater.

I wasn't sure if this would work, but my multimeter showed continuity, so I installed it and hoped for the best.

In proper Roadkill fashion, I mounted the panel itself with a couple of zip ties. With everything back together, I started it up. The voltmeter and oil pressure gauge both sprang to life immediately. I also discovered that the internal lighting is provided by LEDs, and they are bright. And non-dimmable. This made me very glad I mounted them low and out of my direct line-of-sight rather than staring me in the face.

After a few minutes, the temp gauge also started to creep upward. That's all the testing I've done so far, but fingers crossed that everything holds together.

And a small update. After a more thorough test drive, the temp gauge seemed to be reading a little high (~100C), so I grabbed the IR thermometer and checked a couple spots on the engine for reference. The thermostat housing read 95C (which seems a little higher than I would like, but the whole cooling system is new, and the dash temp gauge - the sender for which is in the housing - reads normal), so it's not that far off. Oil pressure seems to be around 3.5bar hot. Voltage is steady at ~14v and reacts quickly when load is applied. Good enough for government work.

Another little problem cropped up, or rather the latest iteration of the problem. The exhaust looks like what you'd expect for something driven year-round in New England. As I've driven the car, it has revealed one weak spot after another. First the resonator came apart at the inlet pipe - I replaced it with a section of straight pipe. Then the flange from the cat to the intermediate pipe started blowing - I chopped that out and sleeved it. Now the muffler is blowing at the bottom where the cradle that attaches to the rubber mounts is welded on, which is pretty minor so far.

But the exhaust suddenly got louder the other day, so I went under and found source was the flange from the downpipe to the cat. I got another sleeve, a couple more U-clamps, and pulled out the Sawzall. Good thing I did this rather than try to remove the bolts and replace the sealing ring - it turned out the downpipe was cracked at the flange. Cut what needed cutting, popped on the sleeve with a liberal coat of anti-seize, and zipped on the clamps with the little electric impact, which solved the problem.

I'm undecided about what to do with the muffler. I either get a universal muffler that fits (~$30) and splice it in, or just spend the extra money to replace the whole cat-back section (~$130). I'll probably just live with it until the weather warms up a bit, unless it decides to get considerably worse.

Pressed the Saab into service to run to Tire Rack over in CT. Both my GF and I needed summer tires, and the BFGoodrich $150 rebate from last week was too good to pass up. Saving the cost of shipping on two sets of tires, plus the lower sales taxes in CT, made driving over to grab them a no-brainer.

The back of this thing is cavernous. Not only did it swallow eight tires, there was no fussing to get them loaded, and I could even see out the rear window without obstruction. It's not a pickup truck or a van, but it's pretty damn useful nonetheless.

I will be happy to pull the studded Hakkas off, though. It's been a warm winter here, and these tires are loud and squirmy at highway speeds.

It is truly impressive how much that swallowed up. 
 

and ingenious solution to the water temp sensor grounding.  

In reply to jfryjfry :

I am pleased with how the temp sensor rig worked out. Signal is clean and consistent, so it seems to be functioning correctly. Actually all the gauges are doing fine, which is rather surprising for them being the cheapest ones I could find on Amazon.

Well, something has gone Quite Really Wrong with the otherwise trusty Saab. Driving home a few days ago I suddenly heard a ticking noise, accompanied by rough running and a loss of power. Given that the exhaust is made up of equal parts rust and hope, I figured it had let go somewhere new, probably very close to the manifold. I got it home, but it wasn't happy.

Fast forward to today. Thanks to the impending plague, I was home, so I got under the car and pulled the exhaust from the downpipe back and fixed (to use the term loosely) the one significant problem area I knew about, then inspected the downpipe, finding nothing leaking. Pulled the plugs, all of with looked fine and equally brownish. Started the engine and pulled one wire at a time: pulling #2 did nothing. Confirmed strong spark at #2 wire. Checked compression on #1 and #2; in spite of my tester being wonky (the Schraeder valve is leaking, so it won't hold a reading), #1 registered ~150#, while #2 registered nothing - not even a twitch. Noticed during test running a significant amount of water out the exhaust.

One way or another the head has to come off at this point, so it's getting a head gasket whether it needs it or not. What I'm concerned about is whether there's some other issue in the valvetrain, or if it's just a bunch of water getting into the cylinder from a blown head gasket. Ticking noise sounds like the top end for sure, so I don't think the bottom end has been affected.

That sucks. I've never done one on a 900C but I'd assume it's easy enough for the access. 

In reply to Stampie :

Yeah, access is not a problem. I've already got the head, intake, and exhaust gaskets and new head bolts here, so I can tear into it whenever time permits. Just have to secure the timing chain so it doesn't slip, but otherwise I think it's pretty straightforward.

Ugh, that's a bummer.  Hopefully it will be something repairable.

If not, I've been seeing This 16V engine in my New England area Saab stuff search for awhile. 

In reply to XLR99 :

Hopefully it doesn't come to that. I did not pay a lot for this car, and the plan was to keep it that way. If it turns out to be something requires actual money I may have to rethink the whole thing. We'll see when I get the head off.

Sorry to hear about the engine. The following link is a good complement to the Bentley:

https://townsendimports.com/Web/engine_folder/headgasket90016v.htm

Thanks for the link. I've read it through, but I'm also looking at this, as it's easier to process and has some useful pictures.

I got as far as pulling the intake and all the ancillaries that have to go to get the head off. Popping the valve cover off revealed no obvious failures, and looking down the plug holes into the cylinders didn't either. I did, however, discover one issue that will have to be addressed (assuming the engine isn't too badly damaged): the timing chain tensioner shows a measurement of 15mm, while the maximum spec is 11mm, meaning the chain is pretty seriously worn. Fortunately chains are cheap and available, and I should be able to roll one in from the top fairly easily. This does not explain why cylinder #2 wasn't firing, but I suppose if it jumped those valves may have hit the pistons. Why it would be those alone, I have no idea, but that's where things are at the moment.

At this point I just have to get the downpipe off the exhaust manifold, pull the cam sprockets and head bolts, and the head should be ready to come off. Stay tuned for the big reveal.

Good news, everybody! I got the head off and located the source of the problem!

The head fought me all along the way. Downpipe nuts were completely rusted on, so I decided to pull the manifold off the head. The exhaust cam sprocket would not come off (bolt stuck), so I just pulled the cam. The head bolts were so tight that a 1/2" breaker bar with a 4ft cheater on it just barely gave me enough leverage to break them loose. I dropped the exhaust to move the manifold far enough out of the way to swing the head up and out. But out it came - eventually.

Once I got it on the ground and flipped it over, the issue became fairly obvious:

I am pretty sure that exhaust valve did not come like that from the factory. Fortunately, there is no other sign of damage anywhere, so I think I may have dodged a bullet with the super-stretched timing chain.

The question now is what to do about the other exhaust valves. My gut feeling is to replace them, but I'm less keen on spending extra money on a car that was supposed to be as cheap as possible. What's the hive consensus here: replace all the exhaust valves, or just the one that cracked? I figure maybe wire brush some of the carbon off the pistons and combustion chambers, clean everything up, new gaskets, new chain - anything else I should do while I've got the head off?

In reply to 02Pilot :

I'd replace them all unless they're really expensive. And great news on the head gasket. 

Edit $25 each at Rock Auto my cheap side comes out and says really inspect the others and replace that one. Then spend the next 5000 miles cringing at every little sound it makes. 

In reply to Stampie :

$14 at FCP Euro. Better, but still $112 on a $700 car.

In reply to 02Pilot :

I could handle that more. 

Anyone know the size difference between the B202 and B235 (9-5) exhaust valves offhand?  I have two extra B235 heads, one of which is already disassembled.

Got the valve out. It is a mess.

Fortunately, it seems to be the only thing that's a mess. A few minutes with a toothbrush and some brake cleaner yielded this:

The biggest fear was for the valve seat, but it looks totally unaffected.

With that dealt with, I cleaned up the head with a pressure washer in the driveway, and then prepped the gasket sealing surfaces for eventual reinstallation. Blasted everything clean and dry with compressed air, then fogged the cams with WD40.

Everything looks fine apart from that one valve. Even the piston and block are apparently unaffected.

So I guess it's now just to clean up the block, replace the exhaust valves (I don't think I can live with just replacing the one that failed), and get everything put back together. Still have no idea what caused the valve to fail.

In reply to 02Pilot :

Momentary lean mixture, or a piece of debris that prevented it from seating hard for a few revolutions are what causes valves to burn away like that. Check the condition of the springs, as a weak spring will contribute to this failure mode.

XLR99 said:

Anyone know the size difference between the B202 and B235 (9-5) exhaust valves offhand?  I have two extra B235 heads, one of which is already disassembled.

Rock Auto didn't have an exhaust valve listed for the 98 9000 B235 but the intake valves are different from an 89 900 turbo. 

Just looked at eEuro -apparently most C900s, all 9000s, and the NG900 both turbo, and NA, use the same exh valve. 

eUro...

Unfortunately I don't have anything compatible sitting in my hoarder's nest of parts

In reply to TurnerX19 :

Interesting. If you look closely at the valve, you can see carbon built up around the area of the failure. That certainly seems to correlate with your suggestion. I will check the springs, but this is not a terribly high mileage motor, and from what I'm able to find, the springs are not often a failure point in any case.

Ordered eight exhaust valves, new stem seals, and a new timing chain. Once they arrive I'll start putting this thing back together.

Quick update. Parts arrived a few days ago. Got the cylinder head all apart and cleaned thoroughly. Lapped in all the valves, old and new; the old intake valves were fine, as were the seats, so lapping was quick and easy. Got the intake side valves installed. Exhausts next, then I'll roll in the new timing chain, clean up the block deck, and finally start bolting this thing back together again.