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Post by valhalla on Jun 8, 2018 23:27:23 GMT 1
A chirp from the ancilliary drivebelt brought me back down to earth - I thought it might be a bit of wax that had got into the pulley grooves or back of the tensioner/idler pulleys. No such luck! That blinking TV-damper runout has come back to bite..... As far as I can tell by LED worklight and eye, whilst the engine is running, my original prognosis of TV-damper misassembly leading to runout is still true; the centre hub of the unit is fine (i.e. the crank is fine) but the outer mass is running-out like fury. It's not just "awkward", it's actually pretty f***ing bad......and the adjacent tensioner pulley just after the crankshaft is having to cope with a cyclic lateral switch in belt-run.
It might not be so clear-cut after my measures with the DTI this evening. The front face of the centre hub of the pulley has a commensurate runout for the amount of runout at the pulley poly-V. However, the chirp from the belt has been tracked to be NOT from the tensioner pulley (much) but in-fact from the belt just glancing the bottom, rear timing case cover when it runs-out with the TV damper rearmost, so a quick adjustment with a blunt drift has got rid of the worst of the symptoms of running-out. I'm going to wait until the new pulley turns-up before removing this one, however I think I missed something on my measurements when I first ground the crank-nose true again.
Then I noticed that the radiator RH side tank (plastic) joint to the matrix has sprung a leak (briefly) - although this dries-up when the rad is hot with coolant..........
Time to hit the bottle now.
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Post by valhalla on Jun 9, 2018 23:44:09 GMT 1
Exhaust system un-bodges this afternoon; a proper hanger for the rear of the system - not a solid strap between the tailpipe and the inner wing!! Plus an investigation into the centre pipe joint that was a bit wobbly near the bridging-piece across the centre tunnel. It turns out that someone has decided that the olive that fits between the two female flares was too effective at doing its job, so they have left it off the car and used a bit of small-diameter exhaust pipe instead. I had an olive in my spares box that is close enough to improve matters considerably until I can source the proper one.
I ran the car up and down the driveway near the workshop, and the vibration levels have definitely reduced. The car is becoming almost civilized now....
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Post by valhalla on Jun 10, 2018 18:52:41 GMT 1
To really civilise the car, I gave her a wash this lunchtime. As the weather has gone a bit overcast, but there is enough breeze to keep the midges at bay, it was an ideal time to do this.
I made some notes as I went around the car. and have a shortlist of those items I will attend-to when the paperwork comes through (if ever) from the DVLA, but overall I'm quite happy with the bodywork. You cannot be too precious about cars up here on Skye, but I reckon I have the makings of a fairly tidy motor, given a bit of spotting-in with some paint and a good polish/wax;
The main item I need to do something about is the bonnet, as it is out of position rearwards (push back by a low-speed impact, I suspect, or during the "recovery" that the car had prior to myself picking her up). The offside is straight along the wing line, but the nearside has a very slight bow upwards.
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Post by valhalla on Jun 17, 2018 21:41:14 GMT 1
I got the car back into the garage this afternoon, having now received the latest-and-greatest kit of TV-damper components/fixings from Germany. These are all Gates branded, so should be good. Certainly they were better quality than the parts I received a couple of weeks ago!
It took about 25mins to get the current TV-damper off the engine, at which point I could see that the fixing methodology was all fine; the thrust-face on the TV-damper was depressed where it touched the crankshaft nose (which I have previously ground back to a smooth finish by whetstone), and the diamond washer was doing its job.
Comparing the new TV-damper to the previously fitted one......very difficult to say whether the improvement I needed to see in Total Indicated Runout (TIR) at the belt grooves to/from the crankcase front face was going to improve over the 56thou" that I currently had.
I loosely bolted the new unit up to the crankshaft. TIR reduced to (wait for it) 52thou". In other words, a total waste of money and time. The jiggered component was the crankshaft.
So being of the red-blooded Engineer persuasion, I refused to take this as the game end. Off I marched to the machine-shop, new Gates TV-damper and dial-gauge units in hand, and mounted the pulley assembly into the lathe 3-jaw chuck. After 10mins, I was able to reproduce the same TIR, but in an opposite sense, at the correct orientation crank-angle;
Having double-checked all the dimensions, which required just over 3thou" to be removed from the crank-nose thrust-face to clean the face up, I then turned the centre of the damper assembly square again to the lathe;
Then re-checking that the outside of the pulley still had 52thou" TIR, and the crank-face had zero TIR, I put this back on the engine. Result! A new TIR, as-fitted, fully-torqued-up, of 6thou".
The auxiliary belt still has a "chirp" but now it is running smoothly and without lateral runout, so the next job is to remove the auxiliary tensioner assembly and check the pulley on it for the 5th time in the last 24hours (it always runs smoothly by hand!!!). Damn thing.............
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Post by studabear on Jun 18, 2018 19:49:15 GMT 1
Wow, that is some serious brain power.
Every credit.
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Post by valhalla on Jun 18, 2018 21:07:20 GMT 1
The chirp saga continues!
I fitted the new auxiliary belt tensioner pulley to the tensioner this morning (right b***** of a job, as I have since fitted a larger diameter OEM oil filter, and all the other bits around the timing belt end of the engine bay are fitted now), and I did just about detect a slight "click" in the original pulley bearing when spun at speed - but nothing much.
Belt back on again, engine starts, 1 minute later, chirp, chirp, chirp.........
The system is all working, I have tried unloading the belt slightly whilst the engine is running, but the dynamics of the auxiliary belt drive are encouraging the tensioner damper to resonate something chronic at idle. As soon as I spray the back of the belt with silicon oil, not a sound out of the system. For 5 minutes. Then, chirp, chirp, chirp!!!!
I think a new genuine Gates or Dayco belt is on the cards here. I might even have a Dayco belt of the correct length in stock at the moment. The current Gates belt has been through the wars on this engine (it was the one fitted when it all stopped a bit suddenly.....) so it might just be that it has a stretch to it that encourages the tensioner to skid when the crank accelerates/decelerates.
The overall noise is reminiscent of the sound that all the 5cyl VW vans used to have, and if memory serves me correctly, they did have a reputation for auxiliary drive noises? A lot of deep "panting" from the lower belt span from crankshaft to A/C transversely vibrating with the torsionals that are going-on here. The Landrover Storm TD5 has some similar issues, but also the Rover TCIe that is contemporary with this engine design, and which also drives the HP fuel pump off another belt from the back of the camshaft.
Good news is that having disturbed the TV-damper over the weekend, the dynamic pump timing has slipped retarded by circa 0.1degree, i.e. nothing to adjust again. Good.
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Post by valhalla on Jul 14, 2018 0:08:00 GMT 1
Well, the chirping was easy to deal-with. A few days after I last posted, the new Gates auxiliary drivebelt turned-up in the post. It took all of 15mins to swap the belts over, confirm that the back of the old belt was more worn than I thought previously (no cracking or grooving, but the dimpling to prevent noise was worn out), and subsequently run the engine to prove no noise any more.
In the last 2weeks, not a single chirp has eminated from the engine bay, and the car continues to run like a dream. The only issue was a lack of registration, due to a total holdup with the transfer of the previous plate off the car (private number). The new number has come through yesterday, so straightaway I got the new plates ordered, and hopefully I can get some serious mileage on this engine before the MoT next month.
The exhaust is cleaning-up quite a bit now. Originally it was wet and sooty, as if the whole system was filled with condensate. The general emissions onto the garage floor were not great either - great puddles of black soot! Since then, the system has got cleaner and cleaner, so I reckon now that with that much storage of soot in the system, either the engine was running like a sack of spuds for a wee while before breakdown (likely, given that the crank pulley was loosening on the woodrough key for a wee while as well), or the subsequent "diagnosis" by the recovering garage also managed to cock things up further (also quite likely.......).
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Post by valhalla on Jul 18, 2018 22:53:26 GMT 1
New plates are on the car! I had to "belt-and-brace" fit the front plate, as the normal adhesive pads I have are not so good where the front bumper curves both horizontally and also vertically, so the plate was trying to make a bid for freedom off the front face of the bumper.
A slight worry was that I had to manually input all the registration details on the Tradex portal for the MID, as the DVLA database was not giving the information for the new number? I have yet to see what the government websites show for the new number, as I'm led to believe that the MoT should have transferred automatically. Whether any remaining tax (5months worth) has been transferred is anyone's guess, so I reckon I'll just wait for the usual DVLA "nasty letter" in the post - explaining how they will fine the pants off me for daring to own a car (or two).
In preparation for the MoT in a couple of weeks time, I ran through all the checkpoints once again, and came to the conclusion that the squeaky Mixo horns were just not going to "cut-it" with the tester on the day, so having gone from two squeaky horns to just one high-tone squeaky horn (repair went wrong) I have decided to fit a pair of good used ones off a slightly later Volvo that should still have the correct 2-pin Econoseal connectors for the harness. Hopefully they will turn-up in the post later in the week, then that ought to give the car a fighting chance of another few years of life.
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Post by develin on Jul 23, 2018 22:16:01 GMT 1
Did you manage to get the MOT?
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Post by valhalla on Jul 25, 2018 20:28:39 GMT 1
It's booked in for next week, Wednesday morning. I will give the exhaust a good blat across the island in the next few days, then hopefully it ought to go through on smoke opacity.
I'm undecided about this car's handling; comparing it to the 2.5petrol that I have, it is a little more ponderous and crashes through the lumps in the road. The engine is a bit heavier, but I reckon the extra 60k miles it has on the clock might have contributed to the rear bushes softening a bit more. Then again, I'm totally unconvinced by the tyres. My petrol V70 has nice, soft East German tyres all round, and they seem to be fine, but this TDI has Pirelli Cinturato's on the front, and they just feel hard and unyielding. I've dropped the pressures slightly on them, but I reckon if this car is a "keeper", I'm going to have to fork-out on some new rear delta-bushes and trailing arm bushes, and just drop the rear axle out for a decent service. Then off to the main garage to have some nice, cheap tyres fitted...
The new horns didn't fit properly at the weekend, so I ended-up backing the pins out of the harness connectors on the car, then potting them into the sockets on the new horns with epoxy. Everything seems to work a lot louder now, so that is less of a concern, but the epoxy I used was not from Mrs. Valhalla's shop (good stuff) but instead off the tool-van (c*** stuff) and was still soft after 24hours. If those pins short together, I'll be jolly baity......
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Post by develin on Jul 27, 2018 15:02:33 GMT 1
Cinturato tyres are okay but not my favourite I must admit, my Subaru has a mix of tyres, it at least the front and rear have the same type and brand and tread pattern.
Always been partial to Toyo extra load bearing tyres for just about anything... also can’t stand low profile tyres but maybe that’s just me...
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Post by valhalla on Jul 27, 2018 23:13:05 GMT 1
I took it out for a "mini-blat" yesterday morning; I had little choice, as dog No.1 had decided to take himself for a walk down to the shop.......So I picked the so-and-so up from outside the shop, then did a quick tour of the local area. All seemed OK until I got back to near-home, where there is a very steep & long drag over the hills to get into the glen, about a half-mile of 10% gradient. I "gave it some welly" for the first time in my ownership of the car, i.e. took it around past 4000rpm in 2nd gear, and there was clouds of black smoke. Stopped and repeated. Same again. General happiness level, around 0.
I picked the dog off the interior door card of the tailgate and carried-on home, feeling that it was not a great idea to take this car in for a MoT at this stage. It was, after all, fully warmed-up for 30minutes, had just done 10miles of driving around the place, up hill and down dale, as they say in rough area of England, and it still didn't present itself very well.
Once I got home, I organised the back of the car to face across the sunshine, and sorted-out the mirror to watch the tailpipe. Free accel smoke was awful to start with, but then I noticed something that I did a load of research on back in the 1990's on a similar fuel pump setup from Bosch. The full-load runout fuel-limiting curve was calibrated by a monkey, and took no regard for what is known in the trade as "dynamical engine speed", or in other words, if the engine speed rises fast, the ECU computes where it is going to be in a few milliseconds time. This TDI does not do that, or not correctly, and hence if you let the engine "bounce" onto the final fuel governor curve, it smokes like a chimney. What I had failed to notice was that I was letting the engine speed rise too far and fast onto the governor curve, almost 4800rpm, and that is way, way too much for a Bosch pump - they are c*** at cam separation of the pumping elements at very high speed, so the timing goes berserk as the plungers try to reconnect to the cam profile, and carries on post-injecting fuel when it should have stopped. It also makes a mess of the cam...... This engine is so smooth and quiet, I just hadn't bothered to look down at the rev-counter, which I should have done! I would never do this to a freshly-rebuilt engine under normal circumstances.
So I modified my free-accel routine ever so slightly, didn't let the engine speed bounce off the governor, lo and behold the exhaust cleaned-up to a light smoke within two free-accels. In other words, most likely to get a pass on the day.
What I reckon I must have done was hit the governor out on the road as well, but there is also a chance that the ageing MAF meter (old "flapper" Bosch unit) has drifted pretty badly. On a free accel, you don't rely on the MAF to control the fuel mass on these older diesels, as the reading always lags the true airflow one way or another, leading to smoke problems as the boost control kicks-in. It looks likely that VW and/or Volvo have missed a trick, but given that only the cylinder head has changed on this engine, and it has never failed on smoke before on any MoT, it ought to go through.
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Post by valhalla on Jul 27, 2018 23:23:22 GMT 1
... also can’t stand low profile tyres but maybe that’s just me... You're not the only one. Living in a rural area, you soon learn the value of decent, tall, compliant bits of rubber on each corner.
At least 3 tourist cars a day "die" with broken alloy rims locally to me. People just cannot believe how poor the roads are on Skye, until they hit a big pothole at speed, and the affected wheel just stays behind...
What compounds things is that all the hire cars are sent out from the big cities and airports in Scotland, all with no spare wheel, no spare tyre, no sealant, no advice......... So it's a long back on a recovery lorry for most of these, generally around 135miles or more, assuming that no local garage is contracted to repair the cars. Most seem to be FIAT 500's on low-profile wheels!!!! What eigit would order a hire-fleet of FIAT 500's without first consulting with FIAT to see if they do a "poverty-spec" Southern Europe wheel/tyre combination? At least some sort of combo that is made to withstand poor roads....
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Post by rhyds on Jul 28, 2018 7:27:44 GMT 1
... also can’t stand low profile tyres but maybe that’s just me... You're not the only one. Living in a rural area, you soon learn the value of decent, tall, compliant bits of rubber on each corner. At least 3 tourist cars a day "die" with broken alloy rims locally to me. People just cannot believe how poor the roads are on Skye, until they hit a big pothole at speed, and the affected wheel just stays behind... What compounds things is that all the hire cars are sent out from the big cities and airports in Scotland, all with no spare wheel, no spare tyre, no sealant, no advice......... So it's a long back on a recovery lorry for most of these, generally around 135miles or more, assuming that no local garage is contracted to repair the cars. Most seem to be FIAT 500's on low-profile wheels!!!! What eigit would order a hire-fleet of FIAT 500's without first consulting with FIAT to see if they do a "poverty-spec" Southern Europe wheel/tyre combination? At least some sort of combo that is made to withstand poor roads.... The best one I saw was near Perth. An older couple were driving a rented Focus and had hit a rock and sliced the sidewall and mullered the alloy wheel. They had a spacesaver spare, and a jack, and even the locking wheel nut key. What they didn't have was a wheelbrace, which I assume was taken out so Hertz were guaranteed to get a phone call if the car had a flat. Of course, this doesn't really work when you're on the top of a perthshire mountain in the rain with no signal. Fortunately a Rover 45 wheelbrace and jack fitted perfectly to get them to the nearest garage.
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Post by valhalla on Jul 28, 2018 23:26:18 GMT 1
The plot thickens with the car. I managed to get some clear road to myself today, same steep hill without a soul in sight. This gave me a chance to try a few different engine speeds and loads, and there is a problem, although I might be able to contain it on the day. There is a fundamental issue with overfueling above 3000rpm, or thereabouts, when the engine is loaded-up steady-state (i.e. not accelerating or decelerating) on a steep hill. This points to an airflow problem, and I know that there are no leaks to atmosphere on any part of the induction circuit (tested as part of the build-up of the engine), so that points to an EGR valve seating problem, or maybe a weak return spring, which means that the boost pressure is bypassing the engine through the EGR valve to exhaust - probably. If it was straightforward boost issue, I would expect to see the MAF readings drop to the point that performance was non-linear.
The first job is to access the valve and test it in-situ with a Mityvac at idle - a thermal scan of the EGR pipework should pick any leakage up past the valve when it is supposed to be closed. More conclusively, I may just blank the valve (temporarily only) and re-test the engine in the same way to see if the smoke levels improve or not. I wouldn't rule-out a sticking or gummed valve here, which would be a nice easy fix, if the MoT was not on Wednesday morning!
The thing that strikes me about this engine/car, is that there is phenomonal torque under part-throttle conditions, so you would not normally see this issue unless you happened to drive agressively most of the time. It means a partial failure of the EGR valve could go undetected by the previous owner for some time.....
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