I recently bought a 2009 Cobalt SS LNF 72,000 miles. I had to get a boost leak repaired (p0299) and the sunroof drain was leaking into the trunk but easy to fix. I'm also about to replace the rear springs since they are collapsed.

Now I'm hearing an intermittent ticking sound coming from the engine. the engine itself has the normal ticking noise you would expect from these motors, but the other ticking noise sounds like something else. No codes or anything and the car runs fine, but I wanted to try to figure it out and see if there's anything I can do since I already had the car in the shop for the p0299.

The only way I can think to describe the noise is like having a piece of card board stuck in a bike wheel and the cardboard is rubbing against the wheel spokes as you ride the bike.

 

My guess is lash adjuster. I've had one making noise in mine for a little while. I'm using AMSOIL Signature Series now hoping that it'll clear up whatever is causing it.

 

Are you sure it isn’t the high pressure fuel pump? They get louder with age and are always quite noticeable.

timing chain tensioner and guide can cause this as well.

 

As it turns out, the noise I was hearing was a rubber coated break line rubbing against my rear driver side tire. I just zip tied it to a safe spot and the noise is gone.

I do think my HPFP is louder than it should be. Doesn't seem to be causing any problems. The owner(s) before me didn't seem to care enough for this car. Glad I rescued it. Thanks for the help.

 

Good find! Yeah my hpfp started getting extra loud about 6years and 80k km into ownership. It is still going strong and survived being tuned at about 400whp for several years. New owner has over 170k on i.

 

It's actually pretty simple to change out the HPFP, and ZZP sells the GM one for $200 (I had to replace mine). The only additional tool you need is the flared nut wrench, size 11/16. Had to change mine out last Sunday since I lost high pressure but still had low.

 

So my next project is a HPFP. I know ZZP sells the GM one for $200. But ZZP has their own for $500. I was planning on getting my LNF to 350 to 400 HP, so if I were to get the $500 one, would that contribute to my goal? I figured getting an ECM tune, injectors and a few other upgrades would go right along with a performance HPFP.

 

Yes, and you would need their Opel injectors + rail with the tune for the 400WHP goal.

 

Oh that's right. I watched a video where the rail was a must. That was also on my list as well as a higher quality intercooler.

So with these aforementioned upgrades, would that put me in the 350 to 400 HP range?

 

need is a strong word. Neither the upgraded pump nor the opel injectors are needed for 400whp on pump gas. The upgraded pump doesnt hurt for extra safety factor. But on non ethenol pump 91/93 low 400whp is very reasonable without fuel system upgrades.
pump is recommended if mixing ethenol as the fuel demand is higher.

 

if your on a stock turbo you will not be able to hit 400whp. There’s a few people that have gotten close absolutely stretching the turbo and ethenol capabilities it the power band is **** as the k04 runs out of breath by 5k rpm.

on 93 pump gas the recipe for 400 whp with the least mods would be.
high flow cat or cat less 3” downpipe. Recommended intercooler and charge pipes as the stock ones are fragile plastic and have a tendency of breaking.
you will need a bigger turbo. Bang for the buck the z54 or z57 turbos are both capable (I ran z54 good compromise and not too laggy) get a zfr if your budget allows. And a good solid tune. Chances are your clutch won’t last long after that but my stocker did hold it right I sold it. All in how you drive and some luck.
Optional extras that will help get you there but not 100% necessary a cold air intake and 3” catback exhaust.
bigger hpfp starts to be needed right after the 400whp point and definitely with ethenol mixes. Opel injectors and or larger fuel lobe cam if you are getting north of the 475 area.

 

Thanks for the info. This narrows down what I will be looking for.

At some point yes I was going for a bigger turbo and better quality charge pipes for sure. There are a few upgrades I was looking to do soon, then some of the bigger HP projects down the road. Sounds like I can replace my stock HPFP with another one, because I don't plan on getting more than 400hp.

 

there are 2 ticking noises the lnf makes. the regular constant ticking of the injectors, and a ticking that sound like a frog that the fuel pump makes. both normal and both heard separately