Alfa Romeo Forums banner

1 - 13 of 13 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
I have an alfa 164 sport 1991 that dropped a valve guide. I tore the entire motor down, pulled the pistons out and re_gasketed the whole thing. I had the machine shop replace the valves and guides as well as mill the head. Now here's the delema, its all back together in factory specifications according to my knowledge but I have a dominate tick coming from my rear head which happens to be the head with new lash caps. The only thing I can think of is that I didn't factor in the material removed during milling when deciding the proper lash cap to install. What do you think? Any advice would be helpful, I put a ton of time love and money into her to be smacking valves again. Thank you in advance for the input!
 

·
Registered
Joined
·
8,784 Posts
How much did you mill the head? A light skim to true it up shouldn't be enough to make valves hit pistons
 

·
Registered
Joined
·
6 Posts
Discussion Starter #3
That was my understanding as well however I cont think of anything else really. I have all manuals required for the 164 however just to clarify, could you give me the proper gap specs for the valve clearance? Seeing as how the manual steered me wrong on the timing chances are it couldve did the same for the valve gap. Thank you again in advance
 

·
Premium Member
Joined
·
27,282 Posts
What are your valve clearances?

That was my understanding as well however I cont think of anything else really. I have all manuals required for the 164 however just to clarify, could you give me the proper gap specs for the valve clearance? Seeing as how the manual steered me wrong on the timing chances are it couldve did the same for the valve gap. Thank you again in advance
So what are intake and exhaust valves clearances now?

Specs are basically

0.018 to 0.019" intakes
0.008 to 0.009" exhaust
 

·
Registered
Joined
·
6 Posts
Discussion Starter #5
When I went to pick up m2 repaired head from the machine shop, we installed the valve buckets without lash caps and measured with feeler gauges to determine it would take a 2.65mm cap per cup to bring it to .019 I'm great with putting the puzzle back together however the tech stuff I trust to the shop. The car also runs great at cruising speeds but idles bad with a check engine light on only at idle. Btw, I wanted to say thank you steve, I've been a member here for a day but I've been using your information for years. Your advice is greatly appreciated.
 

·
Registered
Joined
·
8,784 Posts
We all greatly appreciate Steve's advice:)
I'm confused about the head lash. Were you running the engine without any lash caps? Have you checked the lash?
Have you checked for error codes? When you get the check engine light, you'll have error codes. Have you got the procedure to check them?
 

·
Registered
Joined
·
6 Posts
Discussion Starter #7
I apologize for the confusion. I wasn't running it without lash caps. With the head off we installed the buckets and cam to determine what size caps I needed to order. The 2.65mm caps are in it now. As for the codes, I do not know the procedure for checking them. I have an obd 1 and 2 scanner. Will that work? I know I don't have a plug for it stamped alfa lol. I would love to know how to check them for sure.
 

·
Premium Member
Joined
·
27,282 Posts
How to pull Engine Diagnostics / Check Engine Light Codes

How to pull Engine Diagnostics / Check Engine Light Codes

Self test procedures to pull codes on Alfa 164 models if so equipped.

How to pull Engine Diagnostics / Check Engine Light Codes OBD1

OBD2 did not come into play until 1996.

Here is how you do it on your 91-93 12v V6 model if it has square test button on left side of steering column cover:

Alfa 164 Motronic Self-Diagnosis

Here is how to do it on a 94-95 24v model:

Alfa 164 Motronic M1.7 Self-Diagnosis
 

·
Registered
Joined
·
6 Posts
Discussion Starter #9
Thank you for links, Im going to tear down the intake and double check everything including compression, valve gap and timing at this point. Ill keep you all posted on the findings. Thanks again for all the input, talk to you all soon
 

·
Registered
Joined
·
8,784 Posts
It would be great if you could set up a signature in your posts with your year and model:)
 

·
Registered
Joined
·
6 Posts
Discussion Starter #11
I'll figure out that signature thing for sure. In the mean time, its a 1991 164S 5 speed trans. So, for the update, I tore down the intake, accessed the rear valve train and did a compression check. All 3cys were super low. I then turned my attention back to those valve and I couldn't even get a .08 feeler gauge in any of them. I removed the cam and discovered that the lash cap cup part of was too deep and was resting on the valve seat. I have a164l that I use for spare parts so I measured the caps and sure enough they work. Besides the point, I rebuilt and fired up. Seems to idle and run a ton better but I still have that nasty valve chatte. Compression is back too btw. Any more thoughts on that chatter? Maybe have to break in the new valves?
 

·
Premium Member
Joined
·
27,282 Posts
NO NO no valve break in, they just have to have clearances set up properly.

OK now what are your exhaust valve clearances? They have to 0.0088 to 0.0098" Adjust rocker arms to that spec with two wrenches, one 11mm for nut and small adjustable or abour 1/4" open end to hold adjusting screw as you lock nut with feeler gauge in place betwwen heel of exhaust lobe and adjusting screw. Keep rotating engine clockwise and checking/adjusting all 6 exhaust.

What are your intakes now 0.0188 to 0.0198"? Rotate engine again CW checking all 6 intake intake buckets under heel of intake lobes. As you already know if to tight or loose you have to pull cams to replace shim caps after doing the math doing +/- to old shim cap size to determine correct thickness of new shim.

Report your findings.
 

·
Registered
Joined
·
8,784 Posts
Sounds like your head guy used VW lash caps:)
164s have valve noise normally. Yours may or may not be noisy How loud is loud:)
 
1 - 13 of 13 Posts
Top