3.5 Ticking

[phewop118]

My 01 Intrigue (3.5L, 130k miles) has begun to make a ticking noise. At first, I thought it was low on oil, but that is not the case. The ticking is variable with engine speed and is much more noticeable between 1000-3000 rpm. Above that, it sounds perfectly smooth and revs to redline without any problems. At idle, it can't be heard, but if a load is put on the engine, such as turning the wheel while stopped, and the rpms dip a little, it is heard once again. I'm wondering if this could be the timing chain developing slack from years of full-throttle abuse. Or if it's lifter tick. Or even a small hole in the exhaust manifold? I know it's really hard to diagnose such an issue over the internet, but maybe if someone else has had similar problems, I would know where to begin looking.

Also worth mentioning is that the car sat all winter without being run. In late Feb. I had the waterpump replaced and now drive it about 200 mi per week. Finally, I don't know if it's related, but it seems to run slightly hotter now when cruising, with the temp indicator coming near the 1/2 way mark, whereas it used to stay exactly between 1/4 and 1/2 when driving on the highway.

[phewop118]

Nobody has any info to offer me???? I want to add that it seems to be consuming more oil than normal.

[canatto]

It could be exhaust noise. a cracked manifold or a snapped manifold mounting stud can produce a clicking sort of noise. Do you smell raw exhaust?

[phewop118]

Yeah I just noticed today while sitting at a red light that I could smell exhaust, even with the windows up. I'll do some poking around under the hood when I get a chance later this week.

[panzer dragoon]

I believe it's a pre-ignition condition since it's under a load. =knock sensor (not enough retard) is not working or a possible engine hot spot(carbon build-up -engine may "diesel" or keep running when you turn it off)

Should be burning up the carbon if you run it hard (you do) unless you burn a ton of oil. What is your oil use rate?

[panzer dragoon]

Your burning of oil is creating hot carbon spots on your cylinder head. If I were you I would use an internal engine cleaner or de-carbonizer. I think Valvolene makes a good one at about ~$4. Add the whole thing to a full tank.

You may need to run a fuel injector cleaner ~$1-2 (it's cheaper) every tank or so after that.

[dizzle1]

It sounds like the valvetrain is sticky, also try seafoam

[harmankardon35]

one of the biggest complaints with the 3.5 is oil consumption, and that oil burning (especially if you make primarily short trips without warming the engine fully) will create carbon build up on all the valves, pistons etc. Too much carbon on the piston essentially makes less volume in the cylinder, causing higher compression which can lead to mild forms of spark knock or 'pre ignition', however a code scan is highly recommended to make sure your knock sensors are in good shape. Sea foam (as mentioned) is very good advice. I love the stuff.

[phewop118]

I'm beginning to think that this is definitely an exhaust leak. I can now smell exhaust when the car is sitting still or when the windows are up and I'm driving. Also the noise is getting somewhat worse and is similar to the sound it made when there was a hole in the resonator, except that the noise is coming from the back, driver's side of the engine. If it is indeed the rear exhaust manifold, I may just get rid of the car, as it is quite an expensive repair and the car is getting old.

[harmankardon35]

an exhaust leak on just one cylinder (headers) will cause a ticking noise, an exhaust leak anywhere past that will give you more of a steady sound.

[LittleHoov]

Since you say youre smelling exhaust, I agree with the others, probably an exhaust leak, which leads me to the following:

Do you have emissions testing where you live? The reason I ask is thats the only reason I can think of why you would get rid of it because of an exhaust leak.

I mean...its an exhaust leak, its not a automobile crippling malfunction.

Not trying to sound like a jerk, but just seems like a strange reason to get rid of a car. But like you said its a little old I guess, not quite ten years yet, but I mean in reality you could probably get another 50,000 miles or so out of the thing. I come from the type of folks who often drive cars until the wheels either figuratively or literally fall off, so you can see why I ask the question.

Bottom line, its your car, and you can do whatever you want, its a free country...for now.

[phewop118]

Yes, in pa there's emissions testing. Otherwise I would have no problem keeping the car in it's current condition. It's due for testing in august, but I think it might pass emissions, as pa has a new law that only requires a computer check for codes. However, it would fail the state inspection, which is very comprehensive and stringent. I'm still looking around, but it might be about the same price to buy an LS4 engine and transmission from an Impala Ss or Grand prix gxp as it would be to buy and replace the rear exhaust manifold. Of course this would be a huge undertaking and much of the work would have to be custom, but I don't really need to drive the car anymore, so I could drag it out over some time.

[LittleHoov]

Yeah I figured there was some emissions stuff involved.

An LS4 would be sweet, but like you said entirely custom.

An L67 swap would be a lot more feasible, and pretty capable even bone stock, add in some mods and you can go faster than anyone really NEEDS to go haha

[Tobey]

My 2000 has been doing this exact same thing for the last year. I've been meaning to post about this for a while. The ticking mine is making also seems to be coming from the rear of the engine towards the drivers side. It also becomes extremely noticeable if the engine is idling while under load (in gear, AC compressor on).

I always thought it was an exhaust leak, but today I did some investigating by running water over the exhaust manifold while the engine was running (while it was still cold of course) and I didn't see anything.

I took the plastic cover off the engine and immediately noticed the noise seems to be coming from all 6 cylinders. I'm thinking it's the lifters. At first I thought it was the injectors, but there's no way an injector could make this amount of noise.