Estate Sale Cobra

Hi GRM Forum! Looong time lurker, first time poster. I have been wearing out the search function and finally have a reason to post! 

I purchased this 2001 Cobra with 116k miles about 2 weeks ago at an estate sale in my neighborhood. I had been eyeing the car ever since coming to look a my house before we bought it a couple years ago. It belonged to my neighbor diagonally across the street and I pushed it home.

Last time it ran was at least 3 years ago. According to the previous owner (since 2003) the car was parked in 2020 due to an issue with the steering rack, sat for a couple years where it was started periodically, then eventually it stopped starting. PO was going to sell it for parts and when I said I was interested in getting it back on the road he just about gave me the car. 

He said a mechanic diagnosed "low compression" and gave a 10k estimate for a new motor. He assured me it was never blown up or locked up, just eventually stopped running. The motor turned over fine and the oil looked clean. 

I have been soaking down the rings with Marvel Mystery oil and PB blaster based on the "low compression".

Question for you: I was turning the motor over by hand (with a ratchet) and approximately every rotation of the crank I hear a distinct tick from passenger side cylinder head area. I did hear a very slight tick when I was first looking at the car and turned it over with the starter. Could it be worth it to pull the valve cover at this point? Is this tick maybe related to the low compression? 

New spark plugs get here tomorrow. The old ones were in rough shape -  very black, some rusty and cracked porcelain. The plan right now is to put the new plugs in try to start it, but the tick gives me pause.

Looking forward to sharing my build with you! 

-Doug

A few photos for attention: 2 of the car en situ, one back at home, and a shot of the interior. 

Without hearing the tick it's hard to speculate. Additionally, I don't know the first thing about the 4.6. In theory, you could have a valve stuck open which could be the source of low compression and the tick as it contacts the offending piston. If it were me, I'd pull a valve cover and take a look at what happens when you turn it over by hand. A cheap borescope from that jungle website can give you a look in the cylinders. Knowing what's wrong first could help prevent turning a top end job into a full rebuild. Good luck! 

My guess is timing chain noise from spinning so slow.  I agree that it makes sense to pull the valve cover.  I would just give er hell and see what happens but that's me.

Could be a cam chain tensioner issue, they use oil pressure to tension the cam chains. Tick could be timing chains being loose. 

I would spin it over with the starter but with no plugs in it. Also pull the fuse for the fuel pump. Let it spin over for awhile and try to build up oil pressure and see if the tick goes away or if you can try to pinpoint the location of the tick better.

I agree with the timing chain theories. My 4.6 (2v) chain would slap against one of the guides before building up oil pressure, on a brand new timing setup.

Looks like a great base for a build, please don't LS swap it. 

untchabl said:

Could be a cam chain tensioner issue, they use oil pressure to tension the cam chains. Tick could be timing chains being loose. 

I would spin it over with the starter but with no plugs in it. Also pull the fuse for the fuel pump. Let it spin over for awhile and try to build up oil pressure and see if the tick goes away or if you can try to pinpoint the location of the tick better.

My thought as well, I wasn't sure about the oil pressure part.  After changing the tensioner in M3 it rattled for 15-20 minutes, scared the E36 M3 out of me.  

Thank you everyone for the replies. I appreciate every bit of input!

I looked into pulling the valve covers and that looks like a massive job due to the lack of clearance. Hoping I can hold off on that for a while. 

The plan for this evening is to try and build some oil pressure with the starter (with no fuel - thanks untchabl), investigate my tap further, and continue my penetrating lube soakdown on the rings. If the new plugs show up today, and I have some oil pressure, I'll make another run at starting it. 

Peanutpckrupper - This one is staying Ford powered for sure.

Headphone warning: Loud clunks and other sounds

The "tick" is louder with the sparkplugs out. Speaking of tick, where exactly is the line between tick and clunk?
 

In reply to ZombieSurf :

Sounds like the valve cover needs to come off. I know it's not fun. 
Unfortunately I don't have any guesses that aren't just wild speculation and I'd rather not scare you. Buy or borrow a bore scope before trying to start it. Worst case is you catch something bad early and keep it to just top end work and do it all in the car. 
Could just as easily be nothing, a simple noise from sitting too long. Still, bore scope and valve train inspection is a good idea. 
 

Other than that, way cool car. The 32v is such a great little 8. Super smooth power delivery. And not that I recommend it, but it'll quite easily push trunk/passenger-full cars up pretty good inclines, at 6000'+ doing felony speeds. Not even struggling. Possibly the smoothest affordable domestic power.  

I would describe that as more of a knock than a tick. Sounds like you have parts hitting things they aren't supposed to be hitting to me. 

In reply to ZombieSurf :

I don't know exactly where the tick/clunk/knock line is, but I would say that crossed it. I just PMd you a link to a cheap bore scope that I have been using. 

It may be worth getting a mechanics stethoscope to localize the noise. 

Borescope the cylinders, then its valve cover time.  

I havent gotten that deep into mine, but this may be a good facebook group for specific technical knowledge https://www.facebook.com/groups/2468323130150114/

In reply to barefootcyborg5000 :

Thanks for the encouragement! Going to pick up a bore scope on my lunch break. Valve cover is coming off tonight and I'm not completely dreading it; this is my favorite part of tinkering with a used car - the digging and learning.

I have learned a lot just based on some papers and stuff left behind. One interesting item left in the trunk: Lowering springs and accompanying suspension bits with receipts from 2020. Maybe that's the last time it was on the road? I could probably sell these and recoup most of my investment.

In reply to Motojunky :

I feel like an idiot... where's the inbox? 

In reply to Apexcarver :

Just joined! 

hope something hasn't come loose in the engine!   Following!

and that E series is sweet!

ZombieSurf said:

In reply to Motojunky :

I feel like an idiot... where's the inbox? 

There isn't one. PMs on this board go to the email address you used when signing up. That system is a bit finicky though. Definitely check your spam folder. Regardless of who sends you a PM, the 'from' will look like this:

From:robot@mg.grassrootsmotorsports.com

In reply to dyintorace :

Thank you kindly! 

onemanarmy said:

and that E series is sweet!

Thanks! It's an old church bus that I saved 4 years ago. Just hit 80k miles but I thinks it has 180 on it. Runs great. 

Good news: Valve cover is off and nothing immediately apparent is broken.

Bad news: I turned the motor over by hand and the intake camshaft is not rotating at all. Violent sounding tick coming from exhaust side. 

Bore scope is on the way. I think we will soon find out why it was parked.  
 

With the intake cam not rotating, I suspect the noise is piston hitting some open valves. Not great.

Also, I would have expected to see blue(24lb) injectors in that engine, not orange(19lb).

In reply to gumby :

Thanks for the note on the injectors :) 

Not great indeed. The goal with this project is to push my comfort zone and learn something so I'm right on course in that sense. 

I'm staying positive that the bottom half of the motor is ok? So far the more I peel the worse it gets so we'll see. 

In reply to gumby :

Possible they are an aftermarket? I believe color gets wonky on aftermarket ones

I hope you get this back on the road.  That interior looks mint and I love the warbly sound these 32v cobra engines make.  

So wait, the intake cam is rotating, but not the exhaust?

You have good visibility on the timing chains, what's happening?

Unfortunately, you are looking at head off refresh the valves at a minimum based on what you are saying.