1 00:00:09,416 --> 00:00:09,750 Hello. 2 00:00:09,750 --> 00:00:13,916 Right on this short video, we're going to have a look at engine diagnostics. 3 00:00:13,916 --> 00:00:17,750 Engine diagnostics we've got electronic faults and we've got mechanical issues. 4 00:00:17,750 --> 00:00:22,541 So this one, we're going to do mechanical issues, health check for an engine without stripping it. 5 00:00:22,541 --> 00:00:23,916 Really, there's not many options. 6 00:00:23,916 --> 00:00:27,291 So the one test we're going to do now is we're going to do an engine compression test. 7 00:00:28,250 --> 00:00:31,375 If you've got a cylinder with low compression, it can lead to poor performance, 8 00:00:31,375 --> 00:00:34,041 misfire and other general issues in the engine. 9 00:00:34,708 --> 00:00:37,375 So what we're going to do is we're going to form a compression test. 10 00:00:37,625 --> 00:00:40,541 So first thing's first, we need to remove the spark plugs from the engine. 11 00:01:03,875 --> 00:01:04,791 Right, so removing 12 00:01:04,791 --> 00:01:08,833 spark plugs, keep them in the same order because they'll be going back into the same cylinders. 13 00:01:15,458 --> 00:01:18,833 So we use a socket with a rubber insert in to hold the plugs when we take them out. 14 00:01:19,166 --> 00:01:23,583 What I would advise is that you keep the spark plugs in the same order that we take them out in 15 00:01:23,583 --> 00:01:25,125 so we can then do a visual check. 16 00:01:25,125 --> 00:01:30,541 And if there's an issue on one cylinder we can tell by the condition of the Spark plug what that issue is. 17 00:01:30,833 --> 00:01:34,000 Generally, we're looking for a kind of beige biscuit kind of color. 18 00:01:34,416 --> 00:01:38,791 If they've gone black, then they've got too much fuel or oil running through them. 19 00:01:39,041 --> 00:01:41,166 If they've gone white, then they've overheated. 20 00:01:41,708 --> 00:01:43,291 OK, so this is a good indication. 21 00:01:43,291 --> 00:01:47,541 If the spark plugs are really clean and their old plugs, you could have a head gasket issue. 22 00:01:47,541 --> 00:01:51,125 So I'd be checking the coolant level to see if water's getting into the cylinders. 23 00:01:51,541 --> 00:01:54,083 OK, so we're going to take the other three plugs out 24 00:01:54,083 --> 00:01:57,875 and then just give them a visual check before we start on the compression test. 25 00:02:09,750 --> 00:02:11,375 Yep, that one's good as well. 26 00:02:11,375 --> 00:02:13,583 So we're checking for gap and wear as well, 27 00:02:14,166 --> 00:02:17,916 if they are worn and beyond on their service limits, I recommend replacements. 28 00:02:17,916 --> 00:02:20,333 I would say they're probably getting close to being replaced. 29 00:02:20,791 --> 00:02:24,833 But for the purposes of this test, we can still kind of refit them 30 00:02:24,833 --> 00:02:28,416 just to confirm our results afterwards. 31 00:02:32,958 --> 00:02:36,208 OK, and that's cylinder four, so they're all pretty good, 32 00:02:36,208 --> 00:02:39,791 so they're all kind of running so that's quite a good indication for the state of the engine. 33 00:02:39,791 --> 00:02:42,750 Right what we've done is we've removed the spark plugs. 34 00:02:42,750 --> 00:02:45,500 So now we're going to fit this adapter, which has got the same thread. 35 00:02:45,916 --> 00:02:50,416 And then we screw into the individual cylinder and then we can add our compression gauge 36 00:02:50,875 --> 00:02:52,708 to take a reading off of at the end. 37 00:02:52,708 --> 00:02:57,833 OK, you've got a bar scale on the outside and then we've got a PSI size scale on the inside. 38 00:02:58,166 --> 00:03:01,708 We're generally looking for four readings the same. 39 00:03:01,958 --> 00:03:04,958 Now because it's an older vehicle and it's done quite a lot of miles. 40 00:03:04,958 --> 00:03:09,208 The readings might be lower than a new engine, but that's not necessarily an issue. 41 00:03:09,208 --> 00:03:14,291 As long as all four cylinders are somewhere close, then that's generally a good indication of the health of the engine. 42 00:03:27,625 --> 00:03:30,666 So the basic compression kit will include a standard set of adapters. 43 00:03:30,666 --> 00:03:34,208 Some vehicles, you might need to purchase additional adapters to hook the kit on. 44 00:03:35,333 --> 00:03:39,375 So there are two types of compression tests you can do dry or wet compression test. 45 00:03:39,666 --> 00:03:44,541 A dry test is where we don't press the throttle and we have the the injectors disconnected. 46 00:03:44,708 --> 00:03:49,208 Just crank the engine or a wet test is where we have our foot full down on the throttle. 47 00:03:49,541 --> 00:03:54,083 And that's probably a more realistic kind of diagnosis for the engine to see whether there's any issues. 48 00:03:55,083 --> 00:03:56,791 OK, so we make sure we've got a good connection. 49 00:03:56,791 --> 00:03:59,416 Hand tight is fine. We don't need to over tighten those. 50 00:04:00,041 --> 00:04:05,041 We press the gauge to make sure it is zero'd out and then we have a colleague in a vehicle. 51 00:04:05,625 --> 00:04:09,125 You don't want the vehicle to start because we've taken all the plugs out. 52 00:04:09,458 --> 00:04:10,500 It can't start. 53 00:04:10,500 --> 00:04:12,750 And we've left the coils plugged in. 54 00:04:13,083 --> 00:04:15,916 So from a safety point of view, it's OK to take the test. 55 00:04:16,375 --> 00:04:21,125 What we need to do is crank the vehicle for long enough until the reading settles down. 56 00:04:21,125 --> 00:04:24,541 So if I ask my colleague now to crank the engine then we'll try cylinder one. 57 00:04:30,666 --> 00:04:32,291 OK, thank you. 58 00:04:32,291 --> 00:04:36,166 Right, that's an extremely low reading, and that's not what I'd expect, so what we're going to do 59 00:04:36,166 --> 00:04:39,708 is move on to the next cylinder, double check that reading. 60 00:04:39,708 --> 00:04:40,916 And then if we've got an issue, 61 00:04:40,916 --> 00:04:45,166 we can come back to the diagnostic equipment and check our connections before we do the next part. 62 00:04:45,833 --> 00:04:46,125 Right. 63 00:04:46,125 --> 00:04:50,333 So following on from where we'd hooked the diagnostic equipment up, we had quite low reading. 64 00:04:50,333 --> 00:04:54,375 Checked through it and there was an issue with the connection on this adapter. 65 00:04:54,583 --> 00:04:56,166 So what I've done for the rest of the test 66 00:04:56,166 --> 00:04:59,708 is now I'm going to remove this piece and will directly connect the gauge in. 67 00:04:59,708 --> 00:05:05,833 Okay so we can now hook the gauge up back up to the adapter and repeat the test on cylinder one. 68 00:05:09,208 --> 00:05:12,916 OK, so shows the value of checking things and making sure we've got good connection. 69 00:05:13,125 --> 00:05:14,958 So if we crank the engine now, please. 70 00:05:19,000 --> 00:05:20,166 OK, thank you. 71 00:05:20,166 --> 00:05:22,625 Right, so that's showing 100 PSI. 72 00:05:22,625 --> 00:05:27,375 Fluctuated slightly higher than that, but you need to do your test for long enough for its settle on a reading. 73 00:05:27,708 --> 00:05:30,000 OK, so cylinder one, 100 PSI. 74 00:05:30,291 --> 00:05:33,250 That's not bad for a vehicle that's kind of nine, ten years old. 75 00:05:33,500 --> 00:05:34,875 That's not a bad start. 76 00:05:34,875 --> 00:05:38,666 So we're going to run through now and connect the gauge to cylinder two 77 00:05:38,666 --> 00:05:40,583 and then repeat the tests across the board. 78 00:05:57,958 --> 00:05:58,666 Right, OK, 79 00:05:58,666 --> 00:06:01,791 so we've rectified our poor connection now, in our compression tester. 80 00:06:02,250 --> 00:06:05,833 We've double checked our battery voltage and the connection, so now we can carry on 81 00:06:05,833 --> 00:06:07,583 and proceed with cylinders two, three and four. 82 00:06:08,708 --> 00:06:09,208 OK. 83 00:06:13,958 --> 00:06:14,916 Okay, thank you. 84 00:06:15,166 --> 00:06:17,958 Right, so quite low reading there, we check in with the gague. 85 00:06:17,958 --> 00:06:20,125 It's just creeping up towards the 100 mark. 86 00:06:20,791 --> 00:06:22,750 OK, so we can take that as a note. 87 00:06:22,750 --> 00:06:26,166 That's what I mean about letting the engine settle down before you take the readings, 88 00:06:26,416 --> 00:06:28,875 so we can now move on to three and four. 89 00:06:44,333 --> 00:06:45,375 OK, thank you. 90 00:06:48,916 --> 00:06:50,458 OK, thank you. 91 00:06:50,458 --> 00:06:53,583 Right, so slightly higher for that cylinder, a small variation. 92 00:06:54,000 --> 00:06:55,291 Not a massive issue. 93 00:06:55,291 --> 00:06:58,291 So as long as we're somewhere close with all the readings we can, 94 00:06:58,291 --> 00:07:02,375 then kind of move on to the next part of the diagnostic process. 95 00:07:03,208 --> 00:07:05,583 So just cylinder four to go through now. 96 00:07:09,416 --> 00:07:12,583 So double checking the connections every time, save for false readings. 97 00:07:12,750 --> 00:07:13,666 Okay, thank you. 98 00:07:18,041 --> 00:07:19,083 OK, that's great. 99 00:07:19,708 --> 00:07:20,750 Right, so there we go. 100 00:07:20,750 --> 00:07:23,625 So another reading just around the 100 PSI mark. 101 00:07:23,875 --> 00:07:25,583 So somewhere close. 102 00:07:25,583 --> 00:07:30,708 So for for a full readout on this test, I'd recommend that we do it when the engine's hot as well. 103 00:07:31,000 --> 00:07:34,125 Some vehicles will have less of an issue when the engines are cold, 104 00:07:34,125 --> 00:07:38,083 but as items expand inside can lead to greater clearances later on. 105 00:07:38,291 --> 00:07:39,208 And then we can check it. 106 00:07:39,208 --> 00:07:43,333 I would also be checking the oil and the cooling system to see if there's any cross-contamination. 107 00:07:43,791 --> 00:07:46,958 The next test on from this will be to do a cylinder leakage test, 108 00:07:46,958 --> 00:07:50,791 which we'll cover in another video that involves the same setup. 109 00:07:50,791 --> 00:07:54,083 But we're pressurising in the cylinders to see if there's any gasses leaking. 110 00:07:54,375 --> 00:07:57,541 They can either leak through the dipstick tube or they can leak through 111 00:07:57,541 --> 00:08:00,791 from the exhaust system or back through the oil filler cap as well. 112 00:08:01,250 --> 00:08:05,750 OK, then we can do both mechanical tests, and that saves us having to strip the engine. 113 00:08:05,750 --> 00:08:10,666 From the results from these tests, we can then decide what we've got to ring the customer and advise 114 00:08:10,666 --> 00:08:15,333 we're going to have to dismantle the engine, or we can proceed with some electronic diagnosis instead. 115 00:08:16,333 --> 00:08:17,583 And that concludes this video.