Hey guys I had couple questions bout the flaws or weaknesses of the 7mgte. I have a '91 supra I've had it for sometime. This is the 2nd time I've had this happen to me the car is auto car. My original engine had 110k on it. I have a real bad tapping coming from the exhaust side of the motor. My 1st motor did the same thing i was racing someone, and the trans slipped when the car boosted didn't want to shift then i had the ultra shitty tap, the first time i tried to ease it 2 miles back to my house it got really loud then shut off and couldn't get it back started...left it sit come back out the next day started right up...Could it be a bent valve i haven't pulled the head, my new motor did the same thing couple months ago same side of the motor. but this motor has maybe 15,000 on it...i have turbo back 3" exhaust, intake and K&n filter, other then that cars stock...i don't have boost controller or any of that yet....would the over boost deal bend a valve or more likely spin a rod bearing? I wouldn't think its a rod bearing or anything bottom end since shes not even really past a stage 1 set-up...What are your guys incite on this? I'm looking at pulling the head hoping it didn't mess screw up any of the pistons and getting a rebuilt head to put back on her....whats the best way to tell if valves screwed....like margin wise. Let me know if any of you guys had any similar problems...if its worth messing with or just drop another motor in her. Thanks Matt
A video or sound clip would help.. Having owned 5 mk3s and 2 turbo mk2s, I've never had a tapping sound come from the head. It could be that a bucket shim came off - high rpms could cause this. But, it could also be a early rod knock - haven't had that problem either with 50 track passes on my 7m Mk2.
Has the car been run with a low oil condition?
Might try quick check, pull the exhaust side valve cover and inspect the shims and exhaust cam.
Simple things like an exhaust leak can also sound like a tapping sound.
If you bent a valve, you likely will notice it driving as you will be down on power (because it won't be closing). It will not be a soft tap, but sound like all hell broke loose. As mentioned, a worn shim will have gradually made more noise over time, but likely not all of the sudden and it shouldn't affect drivability. If you spit one, the valve might open a bit which will affect driving.
Have you checked timing to see if the belt may have jumped a tooth?
Sounds like rod knock to me. You must of somehow over stressed or pounded a rod in to submission. Very hard to do with the 7m, but it does happen. To be honest, don't just go throwing another engine in there without taking this one apart and determining if the block is still good yet, or if there is even a major problem. If you simply just drop another engine in, you are dropping another problem in. Rebuilding can be cheaper and easier then just slapping some jdm oil burner back into the car. Best course of action is to get yourself an automotive stethoscope or something comparable and try to find the general area of the block the sound is coming from. I.E., top (head) bottom (block). Then you will know what you need to do. Take it easy with the races. These cars aren't bullet proof.
Sounds like rod knock to me. You must of somehow over stressed or pounded a rod in to submission. Very hard to do with the 7m, but it does happen. To be honest, don't just go throwing another engine in there without taking this one apart and determining if the block is still good yet, or if there is even a major problem. If you simply just drop another engine in, you are dropping another problem in. Rebuilding can be cheaper and easier then just slapping some jdm oil burner back into the car. Best course of action is to get yourself an automotive stethoscope or something comparable and try to find the general area of the block the sound is coming from. I.E., top (head) bottom (block). Then you will know what you need to do. Take it easy with the races. These cars aren't bullet proof.
Did find out yesterday it is a rod knock. Block seems to be fine we already have the motor apart, spun the bearing on # 5 cylinder, started getting new parts figured I'm going to go all out and upgrade all the bottom end while I'm at it. I really was hard on the car when i was younger, now a days i might race it once every couple months, she basically a garage covered car now a days. aftermarket rods wise who makes them?
Personally, I would just go with eagle rods. You could spend up to almost a 1000 bucks on pauter rods, but its a big waste of money for a souped up street machine. Unfortuantly, you will probably have to do much more than just the rods. If you play your cards right, you could rebuild the engine for about 1300. You will need to resurface the head and block, unless it has been done already. You will need new main bearings, rod bearings and gaskets. But of course, if you only want to do the rods you can, but your crankshaft may have some runout so it may spin a bearing again. You should have the crankshaft measured to see if it needs a grind.
Before throwing a bunch of parts at it, what are you looking to get out of it? If this is a fairly mildly built car running a CT-26 or an upgraded one, I think you'll find the money sunk into rods could be well spent on other things. If you're looking to head into territory upwards of 500hp or more, now you're into the range where upgrading everything makes sense.
Personally, I would just go with eagle rods. You could spend up to almost a 1000 bucks on pauter rods, but its a big waste of money for a souped up street machine. Unfortuantly, you will probably have to do much more than just the rods. If you play your cards right, you could rebuild the engine for about 1300. You will need to resurface the head and block, unless it has been done already. You will need new main bearings, rod bearings and gaskets. But of course, if you only want to do the rods you can, but your crankshaft may have some runout so it may spin a bearing again. You should have the crankshaft measured to see if it needs a grind.
Ok, yea a buddy of mine works at machine shop locally, he said around 1300-1400 done right, i figured I'd have to replace all the bearings, but the worse..was the scorching and and gash on the #5 rod. I'll stick with the eagle rods. What is the best metal head gasket to get for the 7mgte, i saw a whole bunch of them 1.0mm, 2.0mm stopper...what would you reccommend there, i ordered everything fro arp bolt wise that i could...and some other things i've had a Lipp Boss turbo (t04e 60-1)sitting in my basement for over a year now, so i'm going to throw her on there too. I just don't want to have this problem agian so i'll do it ight the first time.
Before throwing a bunch of parts at it, what are you looking to get out of it? If this is a fairly mildly built car running a CT-26 or an upgraded one, I think you'll find the money sunk into rods could be well spent on other things. If you're looking to head into territory upwards of 500hp or more, now you're into the range where upgrading everything makes sense.
Yea i do plan on high horsepower goals, only reason i didn't junk the dang thing. when this happened for the 2nd time
Yeah, don't junk her. Here is a drill down of what you should do: Clean up your head real nice. Modding a 7m head is a waste of time unless you want to spend many many paychecks. Mild valve grind, valve stem seals and once again, clean it up nice. I had my engine guy hot tank mine twice until it was spotless. Then I took a dremmel to the chambers and cleaned the carbon out with a nice very very light polishing wheel. It shouldn't leave any marks behind. The only thing really worth doing performance and restoration wise is over sized valves and new guides, but we are talking about $1200 conservative for that. When you do a valve grind, remember to measure for shims, since this is something I forgot and had a noisy valve train. Also, have the head checked for warpage and shaved. THIS IS VERY IMPORTANT. If you do anything, have your head and block shaved. This will prepare it for the metal head gasket and the arp head studs/bolts. Tourque to 75-80 ft/lbs.
Eagle rods. Check crank for run out on both main bearings and journals. If it does need a grind, make sure machinist measures what he takes off so you can get the appropriate sized bearings for both rods and mains. If you really want to go with ARP mains, you can. Just remember, to do it right, you will have to have a line hone of the mains, since the arp studs/bolts will pinch caps out of proportion. ARP mains are really not necessary, you could just go to toyota and order new main bolts. Either way, they must be replaced.
Oil pump. Many people believe in changing the oil pump during a build. I only had 40k on my car, and I put a toga pump in. Personally, just meausre tolerances and compare to the online MK3 tsrm.
Pistons. Up to you what you really want to do. If you want to go the not so price route, go to driftmotion and buy probe forged pistons. I chose weisco, some people like em, some don't. Forged is forged in my book. You could also get a cheaper set of stock oversize pistons if you need to bore from Mahle clevite. Good rings are a must as well.
Block. Have the block checked. A good visual inspection is usually good after a hot tank, since 7m blocks are fairly sturdy in construction. They are very beefy if you look at them. Always chase all threads in the engine, especially mains and deck threads. They are metric! I have heard of some real fools who chased with standard somehow and destroyed their block.
If you are having the engine built by somebody or even yourself, make sure to research any procedures on the engine. There is lots out there.
Head gasket. You might as well go with a metal head gasket. The format is usually recognized as a metal head gasket with arp studs. As stated before, tourqe to arp directions of 80ft/lbs and re tourque after 500-600 miles. Watch the lead foot for about 1000 miles. Reg Reimer recomends 1500 miles with 500 mile dyno oil change intervals without going over 3000 RPM. Hard to do, but your engine will last long. I had my gasket custom made through cometic. They fit it to the exact thickness after I had material taken off of my block and head. Stock thickness of a 7mgte head gasket is 1mm. Whatever your machinist takes off of the head and block will increase the distance between the head and block. Add that number to 1mm and that is what you will need. I was really off with mine, hence why I had to have it custom made. 1.xxmm.
Gaskets. A good gasket kit for the engine build is a must. Gasket kits can be had for about $200. I bought mine from toyota, and spent probably too much.
Any other things you may need in the build, such as bolts and whatnot. If you see somthing rusted and junky, replace it.
You should easily be able to stay under the 1600, 1500 dollar mark if you do these things yourself. Follow all tourque specs and procedures in the tsrm. You will thank yourself later.
I forgot a couple of things myself and now have to do some things I could have accomplishded earlier.
I may have forgot some points, but these guys on here know alot more than I do. I was new to the 7mgte and they filled me in. Ask questions! Better to ask then to do something you will be mad about later.
Yeah, don't junk her. Here is a drill down of what you should do: Clean up your head real nice. Modding a 7m head is a waste of time unless you want to spend many many paychecks. Mild valve grind, valve stem seals and once again, clean it up nice. I had my engine guy hot tank mine twice until it was spotless. Then I took a dremmel to the chambers and cleaned the carbon out with a nice very very light polishing wheel. It shouldn't leave any marks behind. The only thing really worth doing performance and restoration wise is over sized valves and new guides, but we are talking about $1200 conservative for that. When you do a valve grind, remember to measure for shims, since this is something I forgot and had a noisy valve train. Also, have the head checked for warpage and shaved. THIS IS VERY IMPORTANT. If you do anything, have your head and block shaved. This will prepare it for the metal head gasket and the arp head studs/bolts. Tourque to 75-80 ft/lbs.
Eagle rods. Check crank for run out on both main bearings and journals. If it does need a grind, make sure machinist measures what he takes off so you can get the appropriate sized bearings for both rods and mains. If you really want to go with ARP mains, you can. Just remember, to do it right, you will have to have a line hone of the mains, since the arp studs/bolts will pinch caps out of proportion. ARP mains are really not necessary, you could just go to toyota and order new main bolts. Either way, they must be replaced.
Oil pump. Many people believe in changing the oil pump during a build. I only had 40k on my car, and I put a toga pump in. Personally, just meausre tolerances and compare to the online MK3 tsrm.
Pistons. Up to you what you really want to do. If you want to go the not so price route, go to driftmotion and buy probe forged pistons. I chose weisco, some people like em, some don't. Forged is forged in my book. You could also get a cheaper set of stock oversize pistons if you need to bore from Mahle clevite. Good rings are a must as well.
Block. Have the block checked. A good visual inspection is usually good after a hot tank, since 7m blocks are fairly sturdy in construction. They are very beefy if you look at them. Always chase all threads in the engine, especially mains and deck threads. They are metric! I have heard of some real fools who chased with standard somehow and destroyed their block.
If you are having the engine built by somebody or even yourself, make sure to research any procedures on the engine. There is lots out there.
Head gasket. You might as well go with a metal head gasket. The format is usually recognized as a metal head gasket with arp studs. As stated before, tourqe to arp directions of 80ft/lbs and re tourque after 500-600 miles. Watch the lead foot for about 1000 miles. Reg Reimer recomends 1500 miles with 500 mile dyno oil change intervals without going over 3000 RPM. Hard to do, but your engine will last long. I had my gasket custom made through cometic. They fit it to the exact thickness after I had material taken off of my block and head. Stock thickness of a 7mgte head gasket is 1mm. Whatever your machinist takes off of the head and block will increase the distance between the head and block. Add that number to 1mm and that is what you will need. I was really off with mine, hence why I had to have it custom made. 1.xxmm.
Gaskets. A good gasket kit for the engine build is a must. Gasket kits can be had for about $200. I bought mine from toyota, and spent probably too much.
Any other things you may need in the build, such as bolts and whatnot. If you see somthing rusted and junky, replace it.
You should easily be able to stay under the 1600, 1500 dollar mark if you do these things yourself. Follow all tourque specs and procedures in the tsrm. You will thank yourself later.
I forgot a couple of things myself and now have to do some things I could have accomplishded earlier.
I may have forgot some points, but these guys on here know alot more than I do. I was new to the 7mgte and they filled me in. Ask questions! Better to ask then to do something you will be mad about later.
OK yea that doesn't seem to bad at all, Thanks for all the info, I'm sending the engine out to machine shop Monday, the guy i know there told me he'd make detailed notes on crank grinds, etc. I thought internals of 7mgte would be outrageously expensive but really isn't no more expensive then my 350 in my Camaro...I do believe i'm going to go with the weisco pistons, either 83.5mm or 84mm...don't want to go to far then i'll only have little after that if rebuild again. but all the info is very helpful. thanks, now i know where i stand.
Overall, I concur with the general recommendations so far, but I do have some corrections, or personal experiences that differ with some of what was said:
Regarding the head: A good port and polish is more than worth it for high power applications, and is not very expensive. I've seen the dyno of a pair of engines that were both essentially identical running SP 58 kits and tuned to mid/high 400's. Both used identical engine management, the only difference being one had cams with a mild "street" port job, the other a super aggressive "race" port and polish. The cam only engine picked up nicely over what it dynoed the year before at the top end without them once they were tuned, but the aggressive ported engine was still breathing a lot better than even engine with only cams could, although you could see the fall off point where cams could have introduced more airflow that convinced that owner to purchase cams for his next year project too .
In general, most find cams are a not a good bang for the buck, though there is power to be had as you tune and start pushing the flow limits of the head. The oversized valves are also very nice, allow a big increase in breathing room, but are over the moon expensive. A good port and polish though is money well spent in my experience for a high power build.
BTW, the Toyota gasket kit is expensive (I have one on the way myself), but there are several that have had bad experiences with the off brand ones. I am unsure whether the felpro kit is of better quality, but given their name I would think it could be a good compromise.
Yeah, don't junk her. Here is a drill down of what you should do: Clean up your head real nice. Modding a 7m head is a waste of time unless you want to spend many many paychecks. Mild valve grind, valve stem seals and once again, clean it up nice. I had my engine guy hot tank mine twice until it was spotless. Then I took a dremmel to the chambers and cleaned the carbon out with a nice very very light polishing wheel. It shouldn't leave any marks behind. The only thing really worth doing performance and restoration wise is over sized valves and new guides, but we are talking about $1200 conservative for that. When you do a valve grind, remember to measure for shims, since this is something I forgot and had a noisy valve train. Also, have the head checked for warpage and shaved. THIS IS VERY IMPORTANT. If you do anything, have your head and block shaved. This will prepare it for the metal head gasket and the arp head studs/bolts. Tourque to 75-80 ft/lbs.
Eagle rods. Check crank for run out on both main bearings and journals. If it does need a grind, make sure machinist measures what he takes off so you can get the appropriate sized bearings for both rods and mains. If you really want to go with ARP mains, you can. Just remember, to do it right, you will have to have a line hone of the mains, since the arp studs/bolts will pinch caps out of proportion. ARP mains are really not necessary, you could just go to toyota and order new main bolts. Either way, they must be replaced.
Oil pump. Many people believe in changing the oil pump during a build. I only had 40k on my car, and I put a toga pump in. Personally, just meausre tolerances and compare to the online MK3 tsrm.
Pistons. Up to you what you really want to do. If you want to go the not so price route, go to driftmotion and buy probe forged pistons. I chose weisco, some people like em, some don't. Forged is forged in my book. You could also get a cheaper set of stock oversize pistons if you need to bore from Mahle clevite. Good rings are a must as well.
Block. Have the block checked. A good visual inspection is usually good after a hot tank, since 7m blocks are fairly sturdy in construction. They are very beefy if you look at them. Always chase all threads in the engine, especially mains and deck threads. They are metric! I have heard of some real fools who chased with standard somehow and destroyed their block.
If you are having the engine built by somebody or even yourself, make sure to research any procedures on the engine. There is lots out there.
Head gasket. You might as well go with a metal head gasket. The format is usually recognized as a metal head gasket with arp studs. As stated before, tourqe to arp directions of 80ft/lbs and re tourque after 500-600 miles. Watch the lead foot for about 1000 miles. Reg Reimer recomends 1500 miles with 500 mile dyno oil change intervals without going over 3000 RPM. Hard to do, but your engine will last long. I had my gasket custom made through cometic. They fit it to the exact thickness after I had material taken off of my block and head. Stock thickness of a 7mgte head gasket is 1mm. Whatever your machinist takes off of the head and block will increase the distance between the head and block. Add that number to 1mm and that is what you will need. I was really off with mine, hence why I had to have it custom made. 1.xxmm.
Gaskets. A good gasket kit for the engine build is a must. Gasket kits can be had for about $200. I bought mine from toyota, and spent probably too much.
Any other things you may need in the build, such as bolts and whatnot. If you see somthing rusted and junky, replace it.
You should easily be able to stay under the 1600, 1500 dollar mark if you do these things yourself. Follow all tourque specs and procedures in the tsrm. You will thank yourself later.
I forgot a couple of things myself and now have to do some things I could have accomplishded earlier.
I may have forgot some points, but these guys on here know alot more than I do. I was new to the 7mgte and they filled me in. Ask questions! Better to ask then to do something you will be mad about later.
Well got everything apart, found local machine shop to do the work, only thing i wanted to ask so i don't make any mistakes is clarify on the head gasket mess, the stock is 1.0mm, so if i have they guy take off .010 off the head and the block, total between the two, what size HD gasket would i be looking at? Thats the only thing he said he couldn't actually get rods, etc he can get all the brands so its up to me to get it, then he can do it to the specs we agree on, my head and dek aren't warped, motor really doesn't have many miles on it at all, just wanted to clarify so i don't make a mistake.
Yes, you would add the amount taken from the head and the block to the thickness of 1mm. You will have to convert the measurement from the machine shop to metric first, then add. Unless it is already in metric. Basically what your doing is compensating for the material you took off of the engine so you don't change your compression. Then you can look around on some of the websites or what not for a gasket that comes close to the measurment you need. I had mine custom made, it was about .001" off, so I felt pretty happy with the decision. If you need to convert, just type in metric conversion in your favorite search engine and you should be fine.
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7mgte tapping Questions
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