motorgeek.com :: Socially inappropriate motoring information.
Search this topic:
motorgeek.com :: Board index :: The Tech Lounge :: Abnormally aspirated
Post new topic Reply to topic  [ 5 posts ] 

1984 5kST KN engine identification

Author Message
 Post subject: 1984 5kST KN engine identification
PostPosted: Sat Dec 26, 2020 11:45 am 
Offline
Stuck in first

Joined: Thu Aug 21, 2014 4:34 am
Posts: 8
Greetings: I am tentatively dipping my toe into the recovery of a low-milage 1984 5000 S Turbo with a rust-free South Carolina heritage. It has not been registered since 2003. My take from the review I've done is that the in-tank fuel system pump failed and the presence of a massive audio build in the trunk discouraged a replacement because the access was fully blocked. It is clear that before it went idle it received new rotors and pads, and new fuel/oil and air filters. Perhaps a mechanics lien situation?

I've noted a lot of grief spilled over these vehicles on the various boards, much of it based on poor history of the 3-speed auto configuration (... not even considering that its not a stick Quattro). My goal is an honest driver as stock as possible for preservation sake.

My immediate concern is regarding the proper part # for a head on this KN (block # 003881) build. I see references in 7Zap, but nothing matching the currently-mounted 035 103 373 AB head. Similarly, the control pressure regulator (WUR) on the kit ( 063 133 403 A) does not seem to match what is seen on the various parts lists I've reviewed. Concern is that it has been fiddled with, but both of those items look as if they have been installed for a long time.

The head has low compression on #3 cylinder (90#), which is leaking through the intake port, so the head needs rebuild or replacement. Some report there is a lot of flexibility on what is compatible, but nothing convincing me yet.

Any guidance (including "just run") is appreciated.

Happy Holidays!


Top
 Profile  
Reply with quote  
 Post subject: Re: 1984 5kST KN engine identification
PostPosted: Sat Dec 26, 2020 10:42 pm 
Offline
I sprinkle rubber on my Cherios

Joined: Sun May 24, 2009 7:27 pm
Posts: 446
Location: Pleasant Grove, UT
I wouldn't put too much stock in the part number cast into the head and not being able to find the exact numbers on the parts sites. Those numbers seem to vary quite a bit, especially the suffixes.

How low is "low-mileage"? The 5 cylinder engines are VERY robust. It is strange that there would be low compression on any cylinder if it has less than 200K miles on it. The most likely way for that to happen is if it was over-heated and warped the head, or over-boosted, and killed the head gasket or the rings. It could also have lost the timing belt and bent one or more of the valves. If it has been sitting for 17 years, it could even simply have corrosion on the valves, thus causing low compression. Before pulling the head, it might be worthwhile to get a hold of a borescope and see if there's any visible damage or corrosion down there.

I wouldn't worry about WUR and such until you get the compression issue resolved.

I had an '86 5K Turbo that I drove daily for about 5 years. It was one of the most reliable and cheapest cars to drive that I've ever owned. The only problem I ever had with it was when the radiator neck broke off one day. I did a chip and wastegate spring upgrade on it, and it was a lot more fun to drive at that point, even with the automatic. Try to save the car if you can, but not if you think it's going to be unreliable or break the bank.


Top
 Profile  
Reply with quote  
 Post subject: Re: 1984 5kST KN engine identification
PostPosted: Tue Dec 29, 2020 8:28 am 
Offline
Stuck in first

Joined: Thu Aug 21, 2014 4:34 am
Posts: 8
Greetings BlackBox: Thanks or the suggestions The odd reads under 80K, and there cares some indications it might be correct. I am aware that the ODOs are fragile and can easily be disabled, so I'm not betting anything on that. I have had two i5s with over 200k, so am proceeding cautiously optimistic. No borescope handy, but have valve cover off and pressurized cylinder with valves closed and hissing is coming out into the intake side. I am assuming a broken valve (had one on a 90 CQ with almost 300K), but hope not because here that may assume a damaged turbo as pieces exited... Current project is to simply get it running with the low pressure #3 not addressed to see how it looks after a few miles.


Top
 Profile  
Reply with quote  
 Post subject: Re: 1984 5kST KN engine identification
PostPosted: Tue Dec 29, 2020 8:21 pm 
Offline
I sprinkle rubber on my Cherios

Joined: Sun May 24, 2009 7:27 pm
Posts: 446
Location: Pleasant Grove, UT
Yeah, 80K is nothing on those cars. Just running it for now sounds like the best way to proceed. I hope it works out. The '84s and '85s were the "forgotten years" for those cars. It doesn't seem like there's too much information about them, and you don't see them around much. I'm curious, is that '84 intercooled?


Top
 Profile  
Reply with quote  
 Post subject: Re: 1984 5kST KN engine identification
PostPosted: Tue Dec 29, 2020 9:41 pm 
Offline
Stuck in first

Joined: Thu Aug 21, 2014 4:34 am
Posts: 8
Yes, my KH has a intercooler. Standard, according to Bentley.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 
Search this topic:
motorgeek.com :: Board index :: The Tech Lounge :: Abnormally aspirated

Jump to:  



Information

Users browsing this forum: No registered users and 0 guests



You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum
  |  It is currently Thu Jan 21, 2021 7:47 pm
Share |