First Gear Lurching / Surging
 

When I bought my ti, one of the reasons I got the deal that I did was because the car was lurching in 1st gear with moderate to aggressive acceleration. He thought it was the clutch going out, but when I discovered the broken diff mount I assumed that I had found the problem. Nope.

When I take off, the car will sometimes buck and lurch almost like the fuel is getting cut off repeatedly. It doesn't do it every time, it varies in severity and only does it in first gear. Seems more prone to do it when cold and when turning left. It'll sometimes do it when going straight, it hasn't done it yet when turning right. (I haven't driven it enough to know for sure.) Keep your foot out of it and it won't do it at all. Acceleration in 2nd-5th is smooth and strong.

The symptoms don't seem to point to the clutch as the previous owner suspected because when it's real bad it'll actually chirp the rear tires with every lurch. I'm wondering if I've got bad motor mounts and the engine is moving around too much.

Thoughts?

Well, it's plausible. Maybe the broken diff mount caused excessive movement, which caused an engine mount to fail. Or vice versa. Only one way to know for sure.

I plan on getting under it this weekend to check the engine and trans mounts as well as the rubber coupling in the driveshaft (giudo?), u joints and center bearing.

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Salguod;

Guido is a greasy haired, loud-mouthed, New Jersey hipster (or gangster). Guibo is the driveline joint you are referencing... :biggrin:

It seems like the broken diff mount was a symptom, not the issue. Yes, check your motor mounts as well as your trans mounts.

How's your idle, especially after warming up the engine for a few? This issue doesn't "smell" like a clutch, because that would happen after all shifts. I suspect something else, based on what you have posted so far...

Thanks for the guido / guibo clarification. :-D

Idle is perfect, from first start to warmed up.

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When coasting in neutral at 15 mph, the idle should be 1000rpm. This insures smooth driveability at low speeds. Idle drops to 750rpm at stop. Check to make sure the driveline is tight. Guibo (flex rubber coupling can crack or disintegrate), half shafts, center bearing, u-joints, transmission mounts, engine mounts.

I'm gonna get crazy nitpicky here and admonish everyone that it is actually 'Giubo' (pronounced: 'Jew-boh'), and named so after its inventor: GIUnti BOschi.

When you rev the engine while stopped, does it rev smoothly through the RPM range?

I thought that was the spelling, but managed to spell it wrong each time. :tongue:

Idle is as you described, although it doesn't quite rise to 1,000 RPM when moving more like 900. It revs just fine, although I haven't rev'ed it to redline in neutral.

A couple of other notes:

First, there's a clack clack sound up front when turning the steering wheel when stopped or at very low speeds like in a parking lot. I assume this is bad strut bearings and not likely related to the surging.

Second, there is an occasional quiet, dull thud from the rear after I stop. Sometimes immediately after stop, sometimes delayed, sometimes not at all.

Considering the mileage, what I have into it (about $700 so far) and how well it drives aside from this, I'm starting to consider doing the engine & trans mounts, the giubo, the center bearing and the u-joints. They are all original (I got most of the records from new and work with the PO who had it 14 years) and likely very worn anyway. Even if that's $500 in parts, I'll still only have $1,200 into it.

At any rate, I'm not deciding anything until I get under it and look around this weekend.

Didn't have as much time as I thought today, but I did get the front end up in the air and take a quick look. I discovered two things, first the driver's side lower ball joint is loose and second the frame mount on the passenger side for the stabilizer is rusted away. Neither seems like a likely cause.

The giubo and trans mounts look like new, but I couldn't spin the drive shaft to see the whole thing. I hope to get the rear in the air tomorrow to get a better look. It looks like you can't see the center bearing without removing the exhaust, is that right?

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Well, unfortunately, no smoking gun.

Rear suspension is tight all around, nothing loose.

Spun the drive shaft and the giubo looked new all around.

I couldn't see the center bushing without pulling the exhaust & heat shields, so I have no idea how it looks.

After I pulled it off the stands, I opened the hoood and blocked the front tire (parking brake is not working). I then let the clutch out in first, rev'ing the engine to put a load on it while I watched the engine through the hood. No excessive engine movement telling me that the engine mounts are OK. I'm somewhat tempter to take the hood off and watch the engine when it bucks to be sure.

While under the car I did notice two things that I'm not sure how normal they are:

1. If I grabbed the transmission and pushed side to side, there was a decent amount of movement, maybe 1/4" - 3/8" each way. The mounts looked good, but were pretty soft.
2. If I grabbed the half shafts amd pushed side to side, each moved a fair bit as well, the driver's side a bit more than the passenger. Probably 3/8" and 1/4" respectively. No torn boots or axial play.
3. Ahead of the transmission cross member was a lighter duty bracket with two torn rubber mounts on it. Obviously, whatever had been there was gone. Some kind of splash sheild maybe?

I'm not sure what to think at this point. I guess I'm leaning toward u-joints and maybe the center bearing, but that's just a guess. I may have to concede and take it to a shop for a diagnosis.

More info (for anyone still paying attention :smile:). The soft thunk from the rear happens when I put the car in gear. So, car stopped, foot brake applied, clutch in, slide into 1st - clunk. Doesn't happen every time, but most times.

I'm really leaning towards a bad u-joint, which means a new drive shaft (& center bearing & probably giubo). I guess I might just have to drop the exhaust to check it. Sigh.

Does it clunk as soon as you release the clutch after putting it in 1st or the moment it goes into 1st gear only before releasing the clutch?

The TI uses a dual mass flywheel. The dual mass could be separating causing the thug.

Thunk is when it goes into gear before I release the clutch. And the Thunk is definitely coming from the rear. It's not very loud.

The thunk is rear gear lash and is normal on high mileage rear ends. If you get under the car with it in neutral you should be able to turn the drive-shaft a little both ways and feel the gear lash. I would look at engine mounts and transmission mounts for your issue. It sounds like something is moving around when you are in first gear causing the feeling of a lag...

John S

I would agree about the engine mounts, except I'm not seeing excessive engine movement when I hold the car and rev the engine in 1st gear. If the engine is shifting, it ought to do so then as well.

Oh, and it's not a lag, it's hard, tire chirping, lurching. I should try to get it on video.

I should have the car up this weekend to change the control arms, I'll check the lash then.

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Get some video. It should not be chirping the tires unless you do a left foot slide off the clutch pedal otherwise a slam shift.

Here's some video, not the greatest but you should get the point. I tried using the YouTube button, but it didn't seem to work, so I just posted links.

First, moderately aggressive throttle, turning left. You may have to turn it up to hear the engine surge but you can see the car lurch and there's a tire chirp there on the last jump.

https://www.youtube.com/watch?v=MhjHtgL222Y

The video actually makes it look less because you can't feel the car jumping. As you can see I got out of it pretty quick because it just feels horrible. It's actually been worse than this and sometimes it simply doesn't do it.

Next, starting off again turning right. Similar acceleration but very little lurch.

https://www.youtube.com/watch?v=8mYCHSaV8pk

Most of the time there's nothing going right. In a straight line it's in between.

It's driving me nuts as it could be lots of things, but I don't know what it actually is.

Still haven't figured this out yet, but I've learned more and I'm leaning toward engine / trans mounts.

With the cold weather coming in I've found that it doesn't lurch near as much in the cold. Also, I've got a very leaky oil filter housing (about 300 miles to the quart) and the entire underside is coated with oil. When I mentioned this to my friend who was a chassis engineer for Honda he said that it sounded like a rubber bushing problem and that oil will degrade rubber.

You might remember that I said the trans mounts were pretty soft. They are almost marshmallow soft - and coated in oil. I'm assuming that they aren't supposed to be that soft, right?

I've got the new gasket & o-rings for the oil filter housing, once that's fixed I'm thinking trans mounts are next.

Engine mount driver side is completely torn, passengers side most likely torn and trans mounts including Guibo need to be checked.

John S

I believe that's a support bracket for the exhaust.

That's what I was thinking, but there's no brackets on the exhaust itself nor is it loose.

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Dude check the engine mounts, Guibo and trans mount. Although this is a internet guess I bet it is the issue. I reviewed the video and it shows classic sings of multiple torn mounts. I bet the Guibo is trashed...

John S

Engine and trans mounts have been ordered. The giubo looks like new, trans mounts are mushy, but not torn. Hard to get a good look at the engine mounts, but for $50 I might as well change them.

Parts come next week, hope to change them out the following weekend. This weekend is the oil leak at the oil filter housing.

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You will not see the motor move unless you take off the hood and then drive it, there is no way to do it unless you are driving make it buck or lag as you state. Also check that Guibo they are famous for doing exactly what you got going on, when you are under the car checking the Guibo check the trans mounts. I bet you find the issue by looking over all mounting points on trans, driveline and engine. The engine moving around can even cause the accelerator cable to pull the throttle body open causing your issue. I've got a good idea from your videos what is happening.


Good to see you are changing the motor mounts...Just read the post above so I'm adding these comments.

Double check trans mounts with a jack under the rear and push trans up. The trans mounts will look good even when they are torn since when they tear on the bottom they fall right back in place making them look like they are good, also check drive shaft mid bearing and the differential for excessive lash.

What happens if you rev the motor up higher and let the clutch out slower? Does it still buck and lurch?

Best, John S

You nailed it. Driver's side mount was completely separated, but the passenger side was actually still good. Changed the trans mounts too, they were definitely soft compared to the replacements, likely from all the oil that was leaking from the oil filter housing. That gasket, bushing & o-rings were changed as well. As I said before, the giubo looks like new.

I've only driven it about a mile so far, but the lurching appears to be gone. Hopefully I've cured the 300 mile to a quart oil consumption too.