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capableronTRD Regular Location: Brisbane Registered: July 2004	7M-GE Compression results, dodgy?? Wed, 15 December 2004 03:07 Hi all I have a MX83 cressida thats been overheating on longer drives (say over an hour). 2 mechanics said it wasnt a blown head gasket so I've replaced everything else but over $1000 later problem remains (already done fan clutch, thermostat, cap, water pump should be ok (done earlier this year), flushed and new coolant, radiator was cleaned professionally earlier this year, replaced lower hose, and temperature sender unit for instruments).. head gasket was done earlier this year aswell, but as anyone who knows about the 7M engine, well... a blown head gasket is certainly a possibility, or maybe a small crack in the head? especially since ive noticed the car blows bubbles into the overflow tank (exhaust gas getting into radiator??) and there is a residue of what could be oil in the coolant (but NO signs of water in oil or under filler cap). Did a compression test this morning: Method used: Drove car until it started playing up (ie: overheating). Pulled inlet pipe off but left throttle body on. Removed EFI relay (in engine bay fusebox) Removed high tension coil wire. Took out all spark plugs and wires. (hope this didn't matter as opposed to doing each cylinder one at a time) Screwed in gauge, turned car over with throttle wide open until needle stopped moving. Repeated for each cylinder. Results: (cylinder #1 is closest to radiator) Cylinder 1. 15bar (215psi) ON RETEST 14.25bar (204psi) Cylinder 2. 15bar (215psi) ON RETEST 15bar (215psi) Cylinder 3. 14bar (200psi) retest not done Cylinder 4. 14bar (200psi) retest not done Cylinder 5. 13.5bar (193psi) ON RETEST 14bar (200psi) Cylinder 6. 13.25bar (185psi) ON RETEST 14bar (200psi). I looked in the toyota manual and it says minimum 128psi with a maximum difference of 14psi. (but these specs are assuming that the throttle body is removed, i didn't do this, just held the throttle open). So if i've done this correct, does this mean that i have higher than normal compression (which might fit with the fact that the head had some work earlier in the year), but how come cylinder 2 seems bloody high (i tested this one 3 times, all with the same reading too..) Thoughts please anyone?? These readings aren't at all what i was expecting and seem really high...What readings have others gotten on their 7M-GE's?? Cheers. [Report message to a moderator]

	Subject	Poster	Date
	7M-GE Compression results, dodgy??	capableronTRD	Wed, 15 December 2004 03:07
	Re: 7M-GE Compression results, dodgy??	7mgtema71	Thu, 16 December 2004 00:41
	Re: 7M-GE Compression results, dodgy??	CrUZsida	Thu, 16 December 2004 04:46
	Re: 7M-GE Compression results, dodgy??	CLG	Thu, 16 December 2004 05:04
	Re: 7M-GE Compression results, dodgy??	capableronTRD	Thu, 16 December 2004 05:21
	Re: 7M-GE Compression results, dodgy??	CLG	Thu, 16 December 2004 05:27
	Re: 7M-GE Compression results, dodgy??	7mgtema71	Thu, 16 December 2004 05:30
	Re: 7M-GE Compression results, dodgy??	Mr DOHC	Thu, 16 December 2004 07:33
	Re: 7M-GE Compression results, dodgy??	capableronTRD	Thu, 16 December 2004 09:23

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