V1 Strange Idle Issue

[finazzoty]

Not sure why this is occurring, but I’ve got a really rough/“surgey” idle. There also seems to be a “ticking” or light “clattering” as well. Does anyone know what could be causing these two issues? Videos links below (clattering /ticking is audible in the engine close up video):

Rough Idle Issue - Google Drive

drive.google.com

 

[Rauq]

I don't have much insight on the clickety clackity except to suggest you pull the valve cover and have a look around. See if the timing chain feels tight. Have the timing chain guide bolt and the tensioner been replaced? If so, did it run well afterwards but before this?

As far as the surging idle- have you gotten HP Tuners or another scanner hooked up? Any CELs? Any vacuum leaks you can find?

Any more details on the build would be helpful. I see the BRFPR, what's your injector setup? Has it run well before?

 

[Ross]

The clattering might be from a loose cam chain... worn guides, stretched chain, and/or non functioning tensioner.
Also it could be from a valve with too much lash. Not sure if this is an issue with our engines, as I don't know if there is any adjustment on our twin cam engines... but parts still wear, so check the cam for wear, or put a feeler gauge in there, to measure lash.

 

[finazzoty]

So the engine is a completely fresh rebuild - bottom to top. Only original components are pistons, rods, crank and cam gears. Everything else is brand new. I’m wondering if maybe it has to do with the fact that the cams are ZZP stage 2 turbo…?

As for the idle issue…I pulled a scan, got 60ish codes. Then realized I left a few things unplugged, including oxygen sensors. I plugged them back in, let the car run for a bit, repulled the scan and now down to 17 codes. Mostly body module and EVAP stuff. Nothing to indicate there may be an issue. I’ve also got a question in to ZZP about this as they did my tune. I’ve been told this is likely not due to the tune though.

 

[Ross]

You may want to idle the engine with the valve cover off, and see if you can isolate where the noise is coming from. Valves? Cam chain? etc.

The cam chain tensioner is finicky. When new, you lock it with the spring compressed, then install it in the engine, then 'bump it' to get it to release the spring tensioner. If it isn't bumped enough, it stays with the spring locked. You can check it with the valve cover off, turn the crankshaft with a socket to pull on the cam chain, leaving the slack in the chain on the tensioner side of the engine, then check how loose the chain is with a screwdriver. If the tensioner is working, their shouldn't be slack in the chain. If there is, then it may need to bump the tensioner again.

 

[Sluggonaut]

The cam chain tensioner is finicky. When new, you lock it with the spring compressed, then install it in the engine, then 'bump it' to get it to release the spring tensioner. If it isn't bumped enough, it stays with the spring locked. You can check it with the valve cover off, turn the crankshaft with a socket to pull on the cam chain, leaving the slack in the chain on the tensioner side of the engine, then check how loose the chain is with a screwdriver. If the tensioner is working, their shouldn't be slack in the chain. If there is, then it may need to bump the tensioner again.

I just did my timing chain and I used Al from ZZP's method of activating the cam chain tensioner before installing it. This way you know it's activated and it isn't that hard to install activated. You just have to put decent pressure on it to get the threads started.

 

[escapepilot]

Noise - I'd suspect the chain tensioner first.

Idle issue - how long has the engine ran and has the battery been disconnect for some time before you last ran it? Mine always runs rough until it has had time to reset the fuel trims if I disconnect the battery for a while. If I run it for a bit, it smooths out. However, it could be related to the noise issue also.

 

[OptimizePrime]

I’m wondering if maybe it has to do with the fact that the cams are ZZP stage 2 turbo…?

High probability it's not the cams. You can have Stage 2 cams and stock tune and it won't mess with idle to this extent, most of the magic happens in the upper RPM range through the tune.

Does the idle straighten out after you're up to operating temperature?
Is it hard to start?
If you set your idle to like 1k rpm is it smoother?

If you take the valve cover off, first thing to check is your rockers - one may have come off or it's now misaligned. If everything looks good, it very well could be your fuel trims (that won't fix the sounds though).

 

[finazzoty]

Ok so quick update (I'm scratching my head)

I just went out to the car and did the following:
1. Pulled the intake pipe and filter off of the turbo and noticed there was a little bit of oil in the turbo (cold side) and on the silicone coupler. Thought maybe it was oil from the air filter, but there is no evidence (inside the intake tube) of oil between the filter and the intake of the turbo. Could there possibly be an oil leak inside of the turbo? I guess I'll have to ask ZZP about this but its a brand new Z54. Al @ ZZP has said previously that any smoke coming from the turbo at this point is likely just assembly lube burning off. ---- NOTE: I did put a little bit of extra oil in (maybe a cup or two extra - not alot) as I do have balance shafts completely removed. Based on what I read, this is appropriate as less oil is displaced with the removal of the balance shafts. Wondering if maybe this caused oil pressure to rise too much and somehow caused the oil in the turbo housing? Kinda doubt it though.

2. Pulled timing chain tensioner - no issue - it was activated (its the latest generation with the hump on the head of the bolt).

3. Reinstalled tensioner, intake pipe and air filter (after of course wiping out the little bit oil that was inside the turbo housing and coupler).

4. Cranked car. Took 3 times to start and stay lit, but once it did, it ran pretty beautifully (@escapepilot I think you may be right about the fuel trims). Only did the strange surge thing once or twice in a period of 10 minutes or so. -- Upon further inspection, it appears that the clacking noise is almost certainly coming from the transmission or the bottom end of the engine. I got my head right up next to the powertrain and I don't see how its possible it could be coming from the top end. I also put my hand on the end of the transmission and I can "feel" the noise if that makes sense. What is strange to me is that this is a brand new, 0 mile F35 from DF - filled with Redline MT-90 as suggested and sold by ZZP.

5. Anyway, pleased that the idle problem seems to have resolved itself, I walked to the front of the car to take a video, only to immediately notice smoke/steam coming up from behind the seats. Luckily, this was just coolant blasting out of the overflow hole on the coolant tank, and a tank full of E85 preparing to combust. Not entirely worried about this, but still slightly puzzled as to why I'd have coolant overflow.

Really my main concern at this point is the noise

 

[escapepilot]

With the noise in that location, I'd suspect something loose rattling around. Maybe a bolt, maybe something less concerning. Do you have one of those phone borescopes?...or regular borescope for that matter. I don't recall if there is access from the bottom but if so, that would be easier.

 

[finazzoty]

Ok so there has been some development on this issue.
Clatter noise is still a mystery, so I’ll leave that to the side for now.

The surging idle issue:
I pulled another scan from the car and got a P1101 code (attached scan report below). According to Al at ZZP, this is usually caused by a bad MAF reading, as a result of water or oil getting on/into the MAF. Sure enough. I pulled the MAF and there are little spatters of oil all over the MAF and inside the intake tube…again. Well it turns out this oil is coming from then PCV hose that is attached to the valve cover and connects to the breather nipple on the cold side of the turbo. Does anyone know how/why so much oil would be coming through that breather hose? The only thing I could think of was a massive amount of blow-by, but the engine is a completely fresh rebuild with brand new rings so I feel it’s very unlikely that this is the case.

 

[escapepilot]

I believe there is a baffle in the valve cover that is designed to limit oil getting into the PCV system. It is often removed for powder coating the valve cover and is difficult to replace. Could the issue be there?

 

[finazzoty]

That little bit that’s riveted in?

 

[Ross]

Yes the baffle is riveted in. Your excess blow by could be because the rings aren't seated in yet? Also your turbo is pushing the ring blow by beyond the original specs of the LSJ, so some extra blow by is to be expected.
I just put a small air filter on my valve cover, but I hear that excess blow by will cause oil to drip out of this filter. At least it isn't dripping on the MAF.
Maybe install a catch can?

 

[finazzoty]

Yeah that baffle is still in there. Honestly catch can is what I was thinking. @Ross any reason you went with the breather filter instead of a catch can?

 

[Ross]

I didn't want the oil fumes on the MAF & intercooler, and right now I have a stock LSJ, so no need for a catch can yet.

 

[finazzoty]

@Ross I just realized, you may have a point about the rings…a few times now, I’ve had coolant blasting out of the surge tank, presumably because it’s running really hot - which would in turn indicate that the rings are likely still seating themselves. Perhaps the solution here is to just let it continue to run and clean out the intake until it stops accumulating oil in there

 

[Ross]

Coolant out of the surge tank might be an air bubble working its way out of the system, but I don't see how that is related to the rings not sealing.
My red neck solution to air in the coolant is to rev the engine up to 4000 rpm for 4 seconds, and let the water pump push the air thru the system. Then top up the coolant, and try redline (6500 rpm) a few times.

 

[finazzoty]

So I was more so implying that it could have been bursting out because it was getting so hot, and that it was getting so hot because the rings were still breaking in - this could be wrong, but I remember watching some engine rebuild videos where they were saying that when breaking the new rings in, expect it to run really hot because of the excess friction between the new rings and freshly honed cylinder walls.
This is all speculation at this point.

I did go and get a valve cover breather yesterday and capped off the PCV valve on the turbo. This appears to have stopped the oil leak into the intake pipe and the idle issue has substantially improved, but it is still there. Today I’m going to switch back to the ZZP intake pipe, moving the MAF back to where it should be. Hopefully this fully rectifies the issue. Then on to the clacking noise

 

[Gtstorey]

So I was more so implying that it could have been bursting out because it was getting so hot, and that it was getting so hot because the rings were still breaking in - this could be wrong, but I remember watching some engine rebuild videos where they were saying that when breaking the new rings in, expect it to run really hot because of the excess friction between the new rings and freshly honed cylinder walls.
This is all speculation at this point.

I might believe that it would run a little warmer than normal for a few minutes but I don't believe it will run really hot for an extended period. I'm not sure how much you have actually driven it so it might still be an air pocket but it sounds more like a leaking head gasket to me.