Compression problem

[Ryan]

So i finally got around to doing a compression test. I was at my buddy's shop and got 5 out of the 6 spark plugs out and he couldn't get #5 out either without removing the head. I continued on and did the compression test and All cylinders were even but were only putting out 75 psi. Now this seems to be about half of what it should be. What could be causing this? could it be carbon build up on the valves? the car is an '87 NA and only has 61,000 miles. The car was bought brand new by my mom and she never really drove it and never drove it hard at all so it never really cleaned the engine out well. plus both of my parents suck at car maintenance because for the last 30 years my dad has had company cars and my mom just didn't care. Any other suggestions to what it could be? Any suggestions to things I could do to help fix this problem without taking off the head and going into the engine? MY family is in a very poor financial situation right now so im trying to avoid expensive repairs.

Thanks alot

-Ryan

 

[SRZMK3]

my suggestion is to do the oil test. test each cylinder dry, then pour a little oil in each cylinder and test again if no compression is gained then its a valve problem, if you gain compression then your piston rings are the problem.

 

[87GWSupra]

I'm not sure if Toyota calls for this during compression testing but some manufacturers say to have the throttle held open while cranking, this is an often forgotten step. Try that see what happens. Also doing a leak down test is prob a great way to go also along with the oil test that SRZMK3 mentioned. Their are little concoctions of cleaners you can make to let your motor sip slowly through a vacuum hose to help clean out carbon build up on valves and rings. I've seen this work very well on a Volvo, had about 60psi on 2 cylinders ran the cleaner and kicked it back up to almost 200. Ill talk to my engine repair teacher about what he used to do that and try to remember to post it.

 

[ben1984j]

Yeah, even though it's not in the TSRM, I thought I'd heard the same about holding the throttle open while doing a compression test. Also, make sure your battery is fully charged so the starter can crank at full speed.

 

[SRZMK3]

that carbon cleaner you mentioned is called seafoam, it comes in a white can, theres some good examples of how to use it on youtube, the way i do it is by pouring a third of the can of seafoam into a cup and letting the car suck it out of the cup via brakebooster vacuum hose, after its all sucked turn the car off and let it sit for 2 minutes then start the car and after like 10 seconds rev the car and hold it at 3k rpms it looks really bad and a huge ploom of white smoke comes out of the exhaust just keep it at 3k till it clears it sometimes takes awhile. that has helped clean out my engine many times over.


http://www.youtube.com/watch?v=zt_oXKxe3wo&feature=channel this vid seems a bit overkill but he has the right idea.

 

[Ryan]

I did the sea foam idea and have yet to check it. Lots of smoke. I actually heard about it through my brother who says its big in the VW world.

 

[RacerXJ220]

Sea foam just got popular around my area about two weeks ago. It's crazy how I see in on SM now. I wonder which forum started it.....

I know it's not new, but someone did it, then their friend did it, now it's spreading again.

 

[IJ.]

Closed throttle and 1 plug left in would be enough to pull the rest down to 75psi....

SeaFoam=snakeoil, ask yourself where is all the crap it's removing going (hint carbon is damn hard)

Trickling water in through a vac hose has much the same effect, if your engine isn't doing the preignition think I wouldn't bother.

 

[SRZMK3]

seafoam is a proven product and were not talking about having soo much carbon it pre ignites the fuel, were talking about dirty valves that dont seat properly.

 

[Mk3runner]

I used seafoam back in highschool on my old accord to piss off the administration, smoked the whole parking lot out it was damn funny.

 

[IJ.]

seafoam is a proven product and were not talking about having soo much carbon it pre ignites the fuel, were talking about dirty valves that dont seat properly.

Do you actually think about your posts or do you just bang up whatever shit is floating around in your head?

"Proven" by who? "I seafoamed my Chebby right here in da trailer park and the valves done stopped leaking so now I can tow mah home agin" ISN'T proof......

"Carbon that stops valves seating" ummm yeah ok....
"Dirty Intake" = backfires/pops through the intake and first hard pull dead torched valve
"Dirty Exhaust" = dead torched valve

If you're going to post in Tech provide some evidence/data to back your posts if not don't post, you have a history of posting utter and compete garbage knock it off.

As an exercise pull a dirty Intake valve from an engine warm it up then pour some Seafoam on it letting it run off and let us know how much of the deposits it removes...... (hint real time for it to contact the valve will be 1000th of your pour time)

 

[Supracentral]

seafoam is a proven product

Proven bullshit perhaps...

http://www.supramania.com/forums/showpost.php?p=455112&postcount=15

 

[iwannadie]

Seafoam has been all the rage on a jeep forum I go to for years now. Any problem you have they swear a can of sea foam will fix it. The smoke lets you know that it's working.

 

[87GWSupra]

I think this is a dead thread but the cleaner I was talking about is not seafoam. It's just a mixture of about 3 different very strong solvents. Still haven't talked to my teach about what they are. Prob won't cuz I'm lazy. But he's been using it for about 20 years and nothing bad has happened with It. But was good to read opinions on seafoam.