1 00:00:09,125 --> 00:00:10,250 Right, so following it on 2 00:00:10,250 --> 00:00:13,416 from the last video with the unit on a bench, we've now stripped this one further. 3 00:00:13,416 --> 00:00:14,958 It's a different unit. 4 00:00:14,958 --> 00:00:17,833 We're now down to the brass tacks of it. 5 00:00:17,833 --> 00:00:22,125 If you like, you've got the impeller unit itself, we've got the bearing in the press case. 6 00:00:22,125 --> 00:00:26,250 Obviously, that's loose now because we've split the cast iron side of the housing off this. 7 00:00:26,250 --> 00:00:28,666 Ok, so we've still got our oil feed pipe on here 8 00:00:29,375 --> 00:00:32,416 and then we've got our return on that side. 9 00:00:32,416 --> 00:00:34,541 We've got our cold side of the casing. 10 00:00:34,875 --> 00:00:38,500 So if we look on this side, we've got the impeller itself. 11 00:00:38,666 --> 00:00:41,333 Okay, so this is the intake side from your air filter. 12 00:00:42,000 --> 00:00:46,500 So the reason we run an air filter is these veins in here run a really close tolerance. 13 00:00:46,875 --> 00:00:49,041 If any foreign objects, strike those. 14 00:00:49,041 --> 00:00:53,083 It deflects the actual veins and then we start to get noisy operation. 15 00:00:53,291 --> 00:00:57,125 Generally, the boost is still OK because we've got the turbine unit in there, 16 00:00:57,416 --> 00:01:00,916 but it will start to kind of make noise in operation 17 00:01:00,916 --> 00:01:03,791 so the customer will come in and complain of noise under acceleration. 18 00:01:04,333 --> 00:01:08,208 This housing itself, obviously if the veins touch that it will start to wear. 19 00:01:08,416 --> 00:01:11,375 And then any metal that's generated in there, any swarf 20 00:01:11,375 --> 00:01:14,291 will get hoovered through into the engine itself. 21 00:01:14,833 --> 00:01:20,125 Okay, so we can test this with the unit bolted together, we can actually check for play inside that pulley. 22 00:01:20,125 --> 00:01:22,625 Backwards and forwards and up and down . 23 00:01:22,625 --> 00:01:27,958 It's not uncommon to have a little bit of movement in there, purely because we've got no oil feed at the top. 24 00:01:28,625 --> 00:01:32,458 So this bearing won't be running in oil, so it will have a slight bit of movement. 25 00:01:32,458 --> 00:01:37,333 So don't confuse play in there for the unit that needs replacing. 26 00:01:37,458 --> 00:01:38,916 It's not necessarily the case. 27 00:01:38,916 --> 00:01:42,291 You need to check it against the specifications in the manual. 28 00:01:42,666 --> 00:01:46,333 If there is any metal to metal contact there, that unit is going to need repair. 29 00:01:47,083 --> 00:01:48,458 So the cartridge itself, 30 00:01:49,708 --> 00:01:50,958 the bearings are sealed inside. 31 00:01:50,958 --> 00:01:52,958 These are available separately. 32 00:01:52,958 --> 00:01:58,166 You can kind of see with this one, there is some wear to the actual edges of the veins themselves. 33 00:01:58,541 --> 00:02:01,541 And this, in turn, will cause damage or poor or noisy operation. 34 00:02:01,750 --> 00:02:06,375 We've removed the clamps off here so we can now, even though it's got an O ring to hold it together. 35 00:02:06,375 --> 00:02:10,125 We can remove the two parts of the unit, so we've got an O ring seal in there. 36 00:02:11,166 --> 00:02:13,833 OK, if you split this unit, you must replace that O ring. 37 00:02:14,208 --> 00:02:18,916 Any lack of sealing between these two sides of the system 38 00:02:18,916 --> 00:02:21,583 will cause a loss in boost pressure and more. 39 00:02:22,000 --> 00:02:25,000 More worryingly, if it's a diesel engine, there's a good chance 40 00:02:25,000 --> 00:02:28,666 you'll get diesel oil moving into this side of the turbo. 41 00:02:28,875 --> 00:02:32,666 If that happens the engine itself will over rev. 42 00:02:32,666 --> 00:02:34,750 Because diesel engines can run on oil. 43 00:02:35,083 --> 00:02:38,416 It will then start to pick up engine oil from this part of the system, 44 00:02:38,666 --> 00:02:43,791 bypass the governor bypass the fuel system and the engine itself will kind of take off and over rev. 45 00:02:44,458 --> 00:02:47,416 The only way of stopping it is to stall the engine if you can't 46 00:02:47,541 --> 00:02:50,416 by cutting off the airflow or stalling it in gear. 47 00:02:50,625 --> 00:02:55,583 It will bypass the governor and the engine will run until it runs out of engine oil or it explodes. 48 00:02:56,125 --> 00:03:01,125 OK, so another common cause of this with diesels is servicing by overfilling engine oil. 49 00:03:01,416 --> 00:03:04,125 OK, so you need to be really careful on the turbo diesel. 50 00:03:04,333 --> 00:03:08,750 We don't overfill the engine oil and any signs of oil in the intake system 51 00:03:08,750 --> 00:03:13,000 in the air filter or in the turbo itself must be rectified immediately. 52 00:03:13,000 --> 00:03:16,125 If you leave it, there's a good chance that engine will run on its own 53 00:03:16,125 --> 00:03:19,208 engine oil and it will damage various components. 54 00:03:19,208 --> 00:03:22,041 Normally, the turbo impeller gets damaged from overspeeding 55 00:03:22,333 --> 00:03:25,958 and then the oil pressure inside the engine will drop as the oil level goes down. 56 00:03:26,750 --> 00:03:28,833 OK, so we've got the external casing. 57 00:03:29,083 --> 00:03:33,041 So when you send these off to get them refurbished, then they'll strip this, 58 00:03:33,041 --> 00:03:35,875 they'll measure everything and then replace the parts as required. 59 00:03:36,375 --> 00:03:40,291 So this impeller shaft is actually held together with two lock nuts at either end. 60 00:03:40,875 --> 00:03:44,208 And if we were to take these apart, the they're normally a press fit, 61 00:03:44,500 --> 00:03:47,833 then we can separate these parts of unit and test the bearings inside. 62 00:03:48,458 --> 00:03:51,833 Okay, I would suggest generally, once you've got to this stage with the unit, 63 00:03:52,125 --> 00:03:55,000 you're going to be sending it off to get it refurbished. 64 00:03:55,000 --> 00:03:59,333 This part is loose purely because it presses into the cast iron side of the unit. 65 00:03:59,333 --> 00:04:01,166 So this is not a cause for concern. 66 00:04:01,166 --> 00:04:04,375 Now the bearings in this unit actually feel pretty, pretty solid. 67 00:04:04,375 --> 00:04:07,166 There's good movement in them and they're not catching. 68 00:04:07,625 --> 00:04:11,416 But this unit was condemned purely because it had impeller damage, 69 00:04:11,708 --> 00:04:16,583 and it also damaged the engine casing inside, thus leading to premature failure. 70 00:04:17,333 --> 00:04:20,000 OK, so you send your unit off to get it refurbished. 71 00:04:20,000 --> 00:04:23,458 They'll replace the cartridge and impellers and veins as necessary 72 00:04:23,458 --> 00:04:29,666 Rebuild the unit, they'll run it on a bench to test it for fit and efficiency 73 00:04:29,666 --> 00:04:34,583 and then they'll balance it up to approximately 150,000 r.p.m in a rig. 74 00:04:34,583 --> 00:04:38,958 Then they'll reset the unit, put it back together and then ship it out to the customer. 75 00:04:39,708 --> 00:04:42,041 Some units, if you've swapped from one vehicle 76 00:04:42,041 --> 00:04:45,041 to another, this housing, if we push this back together, 77 00:04:46,416 --> 00:04:51,583 if your intake is on the wrong place, we can actually rotate it round without stripping the unit. 78 00:04:52,041 --> 00:04:55,125 So we've had it on some vehicles where we've changed the unit for another one 79 00:04:55,375 --> 00:04:57,833 is by slackening these two plates and the bolts. 80 00:04:58,125 --> 00:05:00,833 We can actually rotate the outer housing to fit it 81 00:05:00,833 --> 00:05:03,375 to the intake pipe of the system of the vehicle we've got. 82 00:05:04,000 --> 00:05:07,291 Okay, but generally as a rule, if it comes from the unit itself 83 00:05:07,291 --> 00:05:10,000 I'd be picking and selecting the one that fits your vehicle. 84 00:05:10,833 --> 00:05:15,125 OK, so that is the turbine impeller and stuff, and there's good reason fitting the O ring. 85 00:05:15,375 --> 00:05:18,833 Once they're fitted once they need to be replaced. 86 00:05:19,166 --> 00:05:21,541 And make sure you use the right type of O ring. 87 00:05:21,541 --> 00:05:23,625 So there's three different colors. We've got brown. 88 00:05:23,916 --> 00:05:29,791 We've got black for just general fuel systems and we've got beige ones which are included for air conditioning. 89 00:05:30,041 --> 00:05:31,708 Don't swap O-rings about. 90 00:05:31,708 --> 00:05:35,500 And if you look closely, you can actually see where there's a mark in that one where it's started to split. 91 00:05:36,375 --> 00:05:38,958 So that wouldn't be a good idea to refit that. 92 00:05:38,958 --> 00:05:42,625 If we refit that and it splits we've then got to the entire unit 93 00:05:42,625 --> 00:05:45,583 back off the vehicle for the sake of probably £3 worth O ring. 94 00:05:46,333 --> 00:05:50,500 Ok, so that's a quick look inside the internals of turbocharging. 95 00:05:50,958 --> 00:05:54,166 Kind of how the system fits together and what we should be checking for. 96 00:05:54,916 --> 00:05:59,958 In the next video, we'll have a look at a dual turbo setup and variable vane system.