Running Rough

Fordy

I have recently purchased and fitted a Z22SE engine with 80k but once started the engine shakes considerably and there seems to be a huge flow from the exhaust. The flow is more like bursts rather than continuous. Any ideas what it could be?

KevinH

Apart from the obvious and simple things to check such as spark plugs, coil pack, coolant temp sensor, IAT sensor and throttle body (which you have probably already done) it may be worth checking the lambda sensors if you have access to OpCom.

Another thing to check (if you're feeling brave) is to ensure the pre-cat hasn't collapsed - have a look at this link https://z22se.co.uk/threads/3-months-of-problems-to-find-it-is-this.11829/

The other possibility is a slack timing/balance chain - have they been renewed?

Hope that may help 🙂

Fordy

plugs, coil pack and throttle body have all been swapped and opcom throws up no codes. I'll try coolant temp sensor and IAT too.

There isnt a pre-cat as i was going to drill it out when I first got the car to find that it didnt exist.

No chain hasnt been renewed, but the next thing on my list was to check the timing.

Another thing to add is that the car has been sat on the drive for around 2 years and a friend reckons it could be the poor quality fuel as its been sat in the tank for a while

Fordy

Checked the timing after work today and the timing is ok. Can anyone think of other things to check?

milo

KevinH said:
the lambda sensors if you have access to OpCom.

Like kev said u need opcom on it. My coupe was running rough etc. Had no eml etc, plugged in my opcom brought up an fault code for lambda senor. Changed it for new ngk one car runs like a dream again.

Fordy

Did that and no codes were present. I’ve tried to upload the video of the exhaust but it says that the video is incompatible

richard165

Fordy said:
Did that and no codes were present. I’ve tried to upload the video of the exhaust but it says that the video is incompatible

post it on YouTube and link it mate

Fordy

https://www.youtube.com/watch?v=oUsO3YZZP-E

Fordy

Will be doing a leak down test tonight, so will post the results

Fordy

Cylinder 1 was leaking slightly out through tb but still within tolerance
Cylinder 2 was leaking badly through exhaust mani
Cylinder 3 and 4 barely leaked

Think the results of the test explain the erratic flow from the exhaust

Fordy

So I've decided to replace the head with a spare that I had previously stripped down.

Do people recommend the genuine GM head gasket set and timing chain kits or are the likes of the FAI sets just as good?

richard165

my chains and gasket were all genuine. to important to risk it imho

Fordy

richard165 said:
my chains and gasket were all genuine. to important to risk it imho

Where did you get yours from Rich?

richard165

straight from the dealer. I wasn't concerned with the cost though.

KevinH

I recommend genuine GM timing and balance chain kits because they fit properly, they last, and once done you'll have peace of mind knowing the job's well done.

Timing Chain Kit - Here (latest spec kit but currently out of stock, they usually get them back in quickly)

Balance Chain Kit - Here

Hope that helps. 🙂

Fordy

Cheers guys.

I’m struggling to find a gm head gasket set online. Is a gm one needed and if so, anyone got a link?

KevinH

Have you tried AutoVaux or GenuinePartSearch?

KevinH

Do you need a full engine gasket set (which includes gaskets for cylinder head, inlet and exhaust manifolds, valve stem seals, EGR and cam cover) or just a cylinder head gasket?

Aluminium cam cover full gasket set - Part # 9194778

Plastic cam cover full gasket set - Part # 93181942

Cylinder head gasket - Part # 93170143

Hope that may help 🙂

Fordy

Cheers for that Kevin.

I'm looking for the full set mate.

AutoVaux only have the Mahle kit