How To Compression Test a VQ

[00:00:00]Welcome back to Nifty Garage. Today we're going to be showing you guys how to do a compression test on a VHR. This is also going to be compatible with your DEES, your RevUps, your HRs, your VRS.

[00:00:09]It's all the same formula for the compression test. So, let's get into the video. Let's show you guys how to get it done and a couple tips and tricks to save you guys time. Number one tool you guys are going to need is a compression test kit. You can go out and buy one at Harbor Freight. You can order one online. If you don't want to buy one, just go borrow one from AutoZone or Riley's, your local um auto parts shop.

[00:00:28]They'll have a compression test for you to use and bring back charge free. All right. So, big key point with doing a compression test is we want to get the motor up to temp. Uh it's going to give us different PSI based on cold or hot.

[00:00:40]We want hot um operating temperature.

[00:00:43]So, I've already let this car idle for about 15 minutes. We're right at our sweet spot. So, we're going to go ahead and turn it off. And now that this motor's warmed up, it'll give us correct readings on our compression test. So, the first thing we're going to want to do is we're going to want to remove both of our intakes. Um, all together, boots, boxes, we're going to take those off.

[00:01:04]And then we're going to take our intake off so that we can access all of our coil packs, pull our coil packs, pull our spark plugs, and then we're also going to pull our fuel pump fuse and our IPDM so that we're in there cranking and we're not sending fuel into the system so it doesn't try to fire. Uh, don't forget that. I'll show you guys that when we get to that step. We're going to put our compression test kit to the side and take off everything we need to take off to prep to test. All right, so the first thing we're going to do is remove both of our intakes. We got a couple 10 ms. On our driver's side, there's one.

[00:01:41]On our passenger side, there should be two.

[00:01:46]This one's already missing one here.

[00:01:49]Hopefully, yours is not missing. Grab a flathead.

[00:01:54]or you can use an 8 mil, whatever you got available.

[00:01:59]Both clamps on the throttle bodies need to be loosened up.

[00:02:04]Grab a pair of needlense and we have two clips we need to remove or little clamps. We'll just slide the clamps up so we can get the little hoses off of the valve covers. You can see this one a lot better. All we're doing is sliding this clamp back so that when we pull it'll come right off. Then we'll remove our MAF sensor plugs. And I always like to flip them up over so they're out of the way.

[00:02:39]Second MAF. Flip it over. Now we can just pull our intakes off.

[00:02:46]They come up and out very easy. I always take it off of the throttle body first and then I'll lift up on the box. So, now that we've got our intakes off, it's a good time to look for cracks uh in your box. Uh broken tabs that'll break here and then you got a hole. Um these like to go bad as well as the boots. You really want to look at the edge here. They'll rip there. And then in the accordion style boot right there, we got a rip. They love to rip here. Uh, [snorts] keep an eye out.

[00:03:17]We'll check both intakes. Make sure that we don't have any more cracks. All right, throw a tray underneath your car just in case you got a lot of pressure built up in your coolant system. You are going to spill coolant no matter what.

[00:03:28]Don't be upset about it. We are going to rebleleed the car after we do a compression test. All right, so now we're going to get our intake off. We're not going to over complicate it. It is not hard to take your intake off. So, we have our two front hoses that go to our valve covers.

[00:03:47]Pull those off the front of the intake.

[00:03:49]And then we have one. It's going to be your closest hose to the front of the motor on both sides. They're going to need to come off.

[00:04:05]Just throw our clamps forward.

[00:04:08]And don't grab this hose with a pair of pliers or something. You're just going to ruin it. So, just pinch and twist.

[00:04:17][snorts] Pull this hose off.

[00:04:20]Don't be concerned with the coolant. Let it drain. [snorts] So, now that we have those two hoses off our uh throttle bodies and we have these two hoses off the front, we have one more hose we're going to take off in the back that comes directly from our Now, this hose is extremely stubborn. It they suck to come off. So, you can try to like grab it with your needlense and help it off while you pull, but you're not squeezing or doing anything crazy cuz you don't want to crack your manifold.

[00:05:04]All right. So, now we're going to take our sensors off of our throttle bodies, both sides.

[00:05:16]Now, we got to take our MAP sensor off of our manifold, which is kind of weird considering it's not a turbo car. Why it's got a MAP sensor, I don't know.

[00:05:25]But then we'll take this sensor off of our solenoid just so that we can pull this harness all the way off and lay it over.

[00:05:37]I just like to tuck this harness behind our actuator. Then we have one more plug for our EVVAP. Move that over. And the last thing we need to remove from the manifold is our evvap line. You can pull on it and then just tuck it up under these power wires.

[00:05:57]Now we're ready to pull our manifold.

[00:06:00]You have five bolts on the top and then two nuts at both ends. We'll zip those off. They're 12 mm.

[00:06:17]All right. So, you got your six top bolts for your manifold. And then you have two nuts. They will fall off when you take the manifold off. So, I like to just take them and throw them on these little posts.

[00:06:27]The magnet will help you.

[00:06:34]Just like that. You should just be able to pick up and take the whole manifold and place it to the side. All right. So, we're going to come in here.

[00:06:43]We have our odd cylinders on our passenger side. So, we have one, three, and five. Unplug all your coil packs.

[00:06:51]Come over to the driver's side of the car. This is our even cylinders. So, we're going to be removing two, four, and six.

[00:07:10]Now, we're going to zip all of our coil packs out. There's 10 mil bolt holding each one in.

[00:07:17]Going to take all our coil packs and set them to the side.

[00:07:39]This is also a good time to look at your coil packs and see if you have bad um tube seals on your valve covers. So, right here, if you get this little bit of oil coil pack, you know your tube seals are going out. So, it's a good time to do valve covers uh and tube seals. All right. So, grab your spark plug remover socket on the VHRs. On a lot of the VQs, it's going to be the the 14 style. Uh throw an extension on it. We're going to remove all six at the same time.

[00:08:17]And again, this is a great time to check your spark plugs. And if they're wet, you know you're running too rich. If they're burnt, you know you're running too to too lean. These are going to be kind of warm. This spark plug looks pretty new. Uh it looks like they were replaced fairly recently. Uh let's remove all six of those. And then the last step is going to be removing our fuel pump fuse from our IPDM. And then we're ready to compression test.

[00:09:04]All right. All right. So, we're going to remove our battery tray. We're also going to remove our cowl cover is also going to come off so that we can access our IPDM. Okay.

[00:09:14]So, you have two tabs at the top right here. You'll push them in and you can pull up on this IPDM.

[00:09:23]You're going to have a clip at the bottom somewhere.

[00:09:29]Go.

[00:09:35]take this cover off. And if we look in here, sorry.

[00:09:42]We are going to be looking for this one right here, our 15 amp fuse for our fuel pump. It's going to be our top fuse right here at the top, our 15 amp. So, we'll pull that one out.

[00:09:57]All right, we got our compression gauge here. We're going to grab our extension.

[00:10:01]And then this is actually one of the fittings that comes in the kits. It's an M12 adapter. We're going to use that because that's our thread pitch for our spark plugs on our VHRs. All right, we're going to start with cylinder one.

[00:10:12]We're going to thread our tester in here. Now, a good thing to remember is you don't want to go extremely tight because there's nothing to break this off. So, just go handtight. That's going to be a good enough seal to get a good reading.

[00:10:30]Then we'll throw our gauge on.

[00:10:34]And now we're going to grab a friend to help us with our compression test. All right. So, we're going to be putting a jump pack on here because cranking speed matters when we're doing a compression test.

[00:10:47]>> So, we want all the power we can get.

[00:10:52]>> Now, the engine has been warmed up to operating temperature. That's good.

[00:10:57]Buddy's going to be in the car. You want throttle pedal to the floor all the way 100% open. You want to open up. Um I I don't know why it matters. It's just the way it's done. Um hold them wide open and then we're going to crank about 7 to 10 times um per cylinder basically until the gauge stops increasing. We want to keep it very similar for all six uh cylinders. So we're going to keep the same formula for each cylinder. all six.

[00:11:28]So, we're going to do about about 7 to 10 actual compression strokes. Um maybe about 7 seconds until the gauge stops increasing is when we're going to stop.

[00:11:39]And then we're going to do our odd cylinders first. We're going to do 1, three, and five. We're going to jump over to our driver's side and do 2, four, and six. Keep a little notepad.

[00:11:46]I'm going to do the same thing and write down our compression for each cylinders.

[00:11:50]You really don't want more than like a 15 PSI gap. That's what factory recommends. So, we're going to read if you got like something crazy like a 50 PSI drop between a cylinder. Motor's probably bad. Something's not sealing correctly. So, let's go ahead and test it and see what we get.

[00:12:14]>> All right, so we're reading about 220 PSI on cylinder one.

[00:12:21]All right. So, we're reading about two say about 225 on the cylinder.

[00:12:44]All right. So, we're reading 220 on that side. All right. On the passenger side, we have 220, 225, and 220, which is within spec, and there's not a huge PSI difference between these three cylinders. So, let's move on to our driver's side and see if we get matching numbers.

[00:13:07]All right, so we got 210 PSI on cylinder 2.

[00:13:24]All right, we got about 208 cylinder 4.

[00:13:31]All right.

[00:13:40]And it looks about 211. All right. So, now we've completed our compression test. Cylinders 1 through 5 and cylinders 2 through six all look healthy. Uh, the biggest gap we have, these are about 210. We'll just say these are all 210 on our driver's side.

[00:13:56]The biggest gap we have is 225 to 210, which is only 15 PSI. That's not a big difference. Uh, typically on a VHR, you're going to be wanting to read anywhere from 180 to 210, um, depending on the gauge that you uh, are using.

[00:14:11]Considering we're anywhere from 210 to 225, this is a perfectly healthy VHR.

[00:14:16]All right, you guys have successfully done a compression test on your VQ. I hope this video helped you guys out. If you guys got any other videos you want to see, let us know in the comments section below. And uh check out our other videos on Nifty Garage. We got anything from DE content to HR content to VHR content. We got VR content coming soon. Stay posted. Have a good one.

[00:14:36]We'll see you guys in the next video.