Suzuki Forums banner

41 - 60 of 88 Posts

·
Registered
Joined
·
89 Posts
Discussion Starter #41
Yeah, I've done this job before....
94978
 

·
Registered
Joined
·
257 Posts
Just removed cap and brought up to temp. Plenty of flow. But some more air bubbles also. I'll keep doing that until I have either no more air bubbles or I keep getting them and then I'll know I'll need to replace the head gasket.
Do you have the tools to perform a compression test? That should tell you what you need to know.
 

·
Registered
Joined
·
8,501 Posts
actually a cylinder leak down would be more appropriate, or a cooling system pressure test... Both these may be available as a rental tool..
 

·
Registered
Joined
·
89 Posts
Discussion Starter #44
Ok summary.
The truck can idle for seemingly all day and have good interior heat.
As soon as I drive it (within 2 miles) it overheats and I lose interior heat.
If the pipe that comes from the back of the cylinder head stops flowing because of a clog in diagram #5, I would have no flow through the radiator or the heater core. All flow would essentially stop. I did not take this part off for inspection. I simply ran an endoscope "to" it and saw coolant in it and went no further.
Do you agree that I may be onto something with removing this part for inspection and flushing with it removed?
  1. 94980
 

·
Registered
Joined
·
89 Posts
Discussion Starter #45
Yes, I can do a compression test and leak down. I'll have to get a cooling system pressure tester.
Never needed one before now. Or a co2 test kit.
 

·
Registered
Joined
·
257 Posts
If the pipe ... stops flowing because of a clog in diagram #5, I would have no flow through the radiator or the heater core. All flow would essentially stop. I did not take this part off for inspection. I simply ran an endoscope "to" it and saw coolant in it and went no further.
Do you agree that I may be onto something with removing this part for inspection and flushing with it removed?
Maybe, but you say you have interior heat on idle. How could you have interior heat without flow to the heater core?

I wondered about compression test v leak down test and there are pros and cons to both, depending on circumstances. That's a good discussion for another thread. Either test will signal whether you have a problem with compression on a particular cylinder. I'd investigate compression (using either test) before pulling diagram part #5 which appears to be hidden in the engine compartment.

So, to try to answer your question -- even if I did find blockage in that coolant part, I'd do a compression / leakdown test, due to the evidence of gasses under your radiator cap. Personally, I'd do the tests before pulling the cooling system apart.
 

·
Registered
Joined
·
257 Posts
GMJoe, I don't mean to make your job more complicated. It's just that when I initially read your first post, I immediately thought head gasket because those are exactly the same symptoms I experienced once in my 79 Prelude. (Don't laugh.) Temp problem was ok around town, but overheated at freeway speeds with funky impacts to my interior heat. Sometimes hot, sometimes cold.
 

·
Registered
Joined
·
89 Posts
Discussion Starter #48 (Edited)
It my have something to do with flow why I have good heat at idle and overheat under load.
Prepping for compression test right now.
#5 can be accessed easily by removing cam positioning sensor, it's just beneath it. As I said earlier though, when I purged the lines with six gallons of water the pipes flowed fine.
I'll post compression numbers when I'm done.
Plus, I want to find out why my fan isn't coming on when overheat occurs.
Or us that fan just for the A/C system?
 

·
Registered
Joined
·
89 Posts
Discussion Starter #49 (Edited)
Ok. Numbering sequentially from front of truck to firewall. Warm engine, all plugs removed, full battery, per service manual.
Oops, no WOT, so those numbers would only get better. Satisfied.
Thoughts?

1- 165 psi.
2- 165
3- 175
4- 165
 

·
Registered
Joined
·
4,768 Posts
compressions are meaningless at closed throttle, they may change significantly WOT, and even drop. please re-do
 

·
Registered
Joined
·
89 Posts
Discussion Starter #51
Already did.
An improvement of about 2 psi per cylinder. So basically nothing.
 

·
Premium Member
Joined
·
1,319 Posts
Nothing makes any sense on this.
Id go with your plan of removing the diaphram, something verwy screwey gowing on hereow.

P.S. too much compression in number three please lower it.

Don
 

·
Registered
Joined
·
89 Posts
Discussion Starter #53 (Edited)
By diaphragm, I assume you mean t-stat.
Next time I have the head off I'll dish out piston #3 a little more. Lol!
 

·
Registered
Joined
·
472 Posts
I had the same issue with mine and it did turn out to be the engine fan clutch not working. Never did see if you mentioned whether you heard it roar and quiet down.
 

·
Premium Member
Joined
·
1,319 Posts
If the pipe that comes from the back of the cylinder head stops flowing because of a clog in diagram #5,
Um, that thingy,
The #5,
. . . . easy on the dishing . . .
;)
Don
 

·
Registered
Joined
·
89 Posts
Discussion Starter #56
Yes, right when I start the cold engine I hear the 'roar' but I thought that was the ac condencer fan as I can see that running.
That said, if the engine overheats the t-stat should open and the lower hose should not be so cool to the touch.
 

·
Registered
Joined
·
89 Posts
Discussion Starter #57
Ah, #5, got ya' Don.
If I'm draining the system again to remove t-stat, thats when #5 is coming off for inspection an head purge. If I see something come out, I'll reinstall t-stat.
I'm going to find the issue and I won't leave this thread in the dark when I do.
 

·
Registered
Joined
·
1 Posts
Ah, #5, got ya' Don.
If I'm draining the system again to remove t-stat, thats when #5 is coming off for inspection an head purge. If I see something come out, I'll reinstall t-stat.
I'm going to find the issue and I won't leave this thread in the dark when I do.
If
Ah, #5, got ya' Don.
If I'm draining the system again to remove t-stat, thats when #5 is coming off for inspection an head purge. If I see something come out, I'll reinstall t-stat.
I'm going to find the issue and I won't leave this thread in the dark when I do.
If you are not overheating at idle but overheating while driving, I will bet everything you have a blockage. Most other culprits will show up at idle also. Maybe your new radiator. Can you fill it in the top and water comes out the bottom? If not radiator, a collapsed hose?
 

·
Registered
Joined
·
257 Posts
The compression test is ok but you still have bubbles, right? I dont remember what you said about coolant loss...

Cannot a head gasket blow out on the exhaust side, introducing exhaust gasses into the coolant, which wouldn't show up on the compression stroke when performing a compression test? Causing a possible airlock?

Otherwise I'm stumped.
 
41 - 60 of 88 Posts
Top