Renix Running Hot

[cruiser54]

You did the right thing. 

[Jeep Driver]

On 7/14/2021 at 6:57 PM, CO MJ said:

I suppose I should send the head off to be checked for cracks

No.

 

Remove the head and take it to a competent local machine shop. 

Valve job and have it resurfaced if no cracks are found. 

Cost should be around $350......it's been a while and prices may have gone up but that will be close. 

[watchamakalit]

8 hours ago, Jeep Driver said:

No.

 

Remove the head and take it to a competent local machine shop. 

Valve job and have it resurfaced if no cracks are found. 

Cost should be around $350......it's been a while and prices may have gone up but that will be close. 

Solid advice. Putting a bad head on a motor will cause alot more aggravation than its worth. Have a capable shop give the head a good work over. Its worth the peace of mind.

[CO MJ]

10 hours ago, watchamakalit said:

Solid advice. Putting a bad head on a motor will cause alot more aggravation than its worth. Have a capable shop give the head a good work over. Its worth the peace of mind.

Thanks guys, will do once the money comes around. Would it be worth maybe looking around the yards or for a local part out to pull another head? 

[Jeep Driver]

1 hour ago, CO MJ said:

Would it be worth maybe looking around the yards or for a local part out to pull another head? 

No. You would not install a used head without having it serviced. 

 

Have your head inspected before you do anything. 

[CO MJ]

3 hours ago, Jeep Driver said:

No. You would not install a used head without having it serviced. 

 

Have your head inspected before you do anything. 

Copy that! Would there be any advantage to a lower mileage head if I could find one and have it refinished? Trying to decide what to do if my head is damaged and unfixable. Or the block for that matter, how does one find cracks that aren't visible to the eye in the head?

[watchamakalit]

8 minutes ago, CO MJ said:

Copy that! Would there be any advantage to a lower mileage head if I could find one and have it refinished? Trying to decide what to do if my head is damaged and unfixable. Or the block for that matter, how does one find cracks that aren't visible to the eye in the head?

Its a process called magmafluxing. However I don't know how it works but it'll highlight the cracks.

[Jeep Driver]

7 hours ago, CO MJ said:

Copy that! Would there be any advantage to a lower mileage head if I could find one and have it refinished? Trying to decide what to do if my head is damaged and unfixable. Or the block for that matter, how does one find cracks that aren't visible to the eye in the head?

Take the head off and read the gasket, chances are it will tell you what you need to know. 

 

If you are getting exhaust gasses in the coolant there is a strong chance you are losing coolant. If you are loosing coolant..........pull all your plugs and read them, if coolant is getting into a cylinder the plug will be exceptionally clean. Read your plugs, that costs you nothing. 

 

Reading plugs, gaskets.......magnaflux..........there is overwhelming information at your fingertips. 

All kinds of vids. 

 

If you think you are a car guy or want to be a car guy...start here, this episode explains magnafluxing .

 

[Jeep Driver]

Here is an example of reading your head/deck/gasket. 

This is the head off my old 2.5. 

Notice the area between cylinders 2 and 3, the area is discolored. 

Notice the plug in cylinder 3, clean. 

 

Gasket was blown between 2 and 3, also coolant escaped into cylinder 3. 

Compression was lost on 2 and 3 as compressed gasses were passed from one to the other. 

 

This is also a reason I would never use a used head without having it resurfaced.....and no, I do not trust a straight edge. This head is surely warped. 

Also, without a resurface, the outside of the pushrod galley, the thin area, you will not get good compression on your head gasket and it will weep oil down the outside of the block. 

 

 

[omega_rugal]

On 7/16/2021 at 3:20 PM, CO MJ said:

Thanks guys, will do once the money comes around. Would it be worth maybe looking around the yards or for a local part out to pull another head? 

 

wait, do a compression test and pull the head to check the gasket, it may be just a bad gasket, try it before you dump the dough into it

[CO MJ]

1 hour ago, omega_rugal said:

 

wait, do a compression test and pull the head to check the gasket, it may be just a bad gasket, try it before you dump the dough into it

Forgot to say look for a lower mileage head. My engine has 150k and if I'm going to pull the head anyways would a lower mileage head make any difference?

 

Edit: I also did a compression test a few weeks back and I was getting good even compression across all 6. I have not done a leak down. My spark plugs also looked great. I'll check again soon though to see if that's changed

[omega_rugal]

26 minutes ago, CO MJ said:

Forgot to say look for a lower mileage head. My engine has 150k and if I'm going to pull the head anyways would a lower mileage head make any difference?

 

Edit: I also did a compression test a few weeks back and I was getting good even compression across all 6. I have not done a leak down. My spark plugs also looked great. I'll check again soon though to see if that's changed

 

 

oh you did? well then it may be a cracked head after all

[Jeep Driver]

12 hours ago, CO MJ said:

Forgot to say look for a lower mileage head

Bear in mind the cost and time, time is money. 

 

Cleaning, cleaning materials. 

 

Intake and exhaust gasket. 

Head gasket. 

Valve cover gasket. 

Head bolts. 

Oil and filter change.

Coolant. 

Repair any parts damaged in the process, vacuum tubes, sensors........etc......

 

Couple of extra quarts of oil to flush pan if contamination occurs. 

If oil contamination occurs you'll need a second oil change. 

 

Retorque head bolts after a couple of heat cycles. 

 

My point is that half-@$$ is expensive. 

[CO MJ]

Finally finished the head gasket, but it looks like I'm still running hot. I've been maybe 5 miles and temp gauge is still high and matches my IR thermo. Any thoughts? I went with all new hardware, had  the head magnafluxed and leak checked, new gaskets, vacuum lines, flushed all the cooling passages including the block, bled through the temp sensor on the block, and I was very thorough installing everything.