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| | | blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | I'm gonna be replacing head gaskets soon. Is it best practice to replace the inlet manifold bolts as well as the head bolts or should they be fine to re-use?
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Feb 2019 Posts: 29 newbie | newbie Joined: Feb 2019 Posts: 29 | I'm assuming you have a leaking head gasket?
Sometimes you can fix those without removing the head.
If the head bolts are not the one and done type, i.e. reuseable you can start at the center and using the pattern recommended retorque each one, one at a time. Believe the chevy head bolts go through into the water jacket so you'll have to drain the coolant and pull the bolt and put sealer on it. But do one at a time. Take it up to 20-23 lbs and then one swing of the torque wrench take it to the full value, has to be one swing, don't stop. Do each one this way then do a pressure test on the cooling system to see if it is fixed.
I've done this and saves mucho time and works.
If yours is the '79 vintage they should be reusable. If you change to studs you might have better luck on the above method. | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | Thanks Marcela, I’ll give that a go. Just want to clarify this bit †If you change to studs you might have better luck on the above method. “ I presume you mean head bolts rather than studs. Or do you mean switch the bolts for studs? I have bought a new set of head bolts so will use them one at a time with sealer and re-torque as you’ve suggested. Cheer’s for the reply.
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Feb 2019 Posts: 29 newbie | newbie Joined: Feb 2019 Posts: 29 | Bolts work fine. Studs can work better, better clamping. But bolts will work fine for what you are doing. Let us know how it turns out. | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | Cool I'll try it with the bolts I have. I'm hopeful as it doesn't seem like too much water is getting in the oil. There's a bit of emulsion inside the filler cap but nothing too bad.
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Sep 2005 Posts: 9,855 Likes: 234 carpal tunnel | carpal tunnel Joined: Sep 2005 Posts: 9,855 Likes: 234 | Shaggy have you verified it's a head gasket and not the intake gasket? Did you find a wet spark plug or water in one of the cylinders? Just a thought. | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | Hi Catfish, No I haven't started into it yet. I'll do a compression test , check the plugs and I can probably get a loan of a cheap borescope too.
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Feb 2019 Posts: 29 newbie | newbie Joined: Feb 2019 Posts: 29 | I'd do a pressure test of the cooling system or bypass that if not needed. A leak down test over a compression test is what i prefer. | | | Re: blown head gasket :eek: | Joined: Sep 2005 Posts: 9,855 Likes: 234 carpal tunnel | carpal tunnel Joined: Sep 2005 Posts: 9,855 Likes: 234 | Pressurize the cooling and look for water or signs of moisture in the cylinders. It may save you some headaches if (fingers crossed) there's none there. I've had intake gaskets leak water before and it's very disturbing to see it happening to do leanbh!
Last edited by CatFish; March 03rd 2019 10:15 pm.
| | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | "To do leanbh" . You speak Irish Catfish?
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Feb 2019 Posts: 29 newbie | newbie Joined: Feb 2019 Posts: 29 | If you do a pressure test on the cooling system and it shows losing pressure, do a leak down test on the cylinders and it will show you which one or if they are all good, then it is the manifold or some other source. | | | Re: blown head gasket :eek: | Joined: Sep 2005 Posts: 9,855 Likes: 234 carpal tunnel | carpal tunnel Joined: Sep 2005 Posts: 9,855 Likes: 234 | "To do leanbh" . You speak Irish Catfish? Naw. But my grandfather did. And his father, and his father, ...... | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | I did a compression test and all cylinders seem good. Gonna do a pressure test on the cooling system and a leak down test and see if I can pinpoint where the issue is.
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Jun 2010 Posts: 18,286 Likes: 559 | Joined: Jun 2010 Posts: 18,286 Likes: 559 |
SUNSHINE VANS-VAN DIEGO ADRENALIN BY THE GALLON & CHASIN RACIN ONE FOR THE DIRT & ONE FOR THE STREETS '93 CHEVY G30 454 4X4 SPORTVAN EXT 146" WB '92 CHEVY G30 454 BEAUVILLE EXT 146" WB | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | Yeah that's what I was thinking frscke1. If I bypass the heater core by just connecting the hot-in and cold-out water lines back to back and refill the radiator overflow bottle then I can see if the level drops over time and that should tell me. I have a feeling I ran it like that before though and was still losing coolant.
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | So ... the heater is disconnected /bypassed so it can't be a leaky heater core. I guess that means inlet manifold is the most likely culprit.
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Mar 2019 Posts: 130 Likes: 3 member | member Joined: Mar 2019 Posts: 130 Likes: 3 | Lilse tools makes a kit 75500 which is an exhaust tester for the cooling system so if its impossible to do a cylinder leak down test its always another option to help determine if you do have compression loss into the cooling system. | | | Re: blown head gasket :eek: | Joined: Nov 2013 Posts: 2,286 Likes: 153 veteran | veteran Joined: Nov 2013 Posts: 2,286 Likes: 153 | Hidee Ho Shaggy, Long, long ago in a Land far away, a wounded 1969 327 smallblock rebuilt by my FIL, was losing coolant, powering a 1970 Chevy C10 down the road. This was unacceptable on a 90 mile daily commute. Take a quick look into the radiator with the engine running, at operating temperature, radiator cap off. Check for exhaust entering the coolant. It will be readily apparent. Have a friend apply throttle, engine in park, parking brake on, safety first. Look for tiny bubbles! If you see them increase when the motor revs up, hate to say, but the heads probably should come off that motor. Mine were still fine, but don't let that motor overheat. Yes you can reuse intake bolts. Clean all inspect threads well, pay special attention to the proper gasket installation, torque, and don't misalign the intake valley gasket putting the intake on. That Sucks... Just use proper attention to detail upon reassembly, and you'll be fine, (FIL Leonard at Precision Engine...) Lucky for me, since I knew who rebuilt mine, I brought it up on occasion! The fun part upon reassembly on a Chevy smallblock is hydraulic valve lash adjustment! Chevy Tip: Take an old pair of steel valve covers, and cut the tops off, bolt them on first, way less smoke that way. Good Wrenching! | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | My thinking is that seeing as I have good compression on all cylinders that doing a leak down test wont tell me anything more. That said I have a loan of a leak down tester so I may as well use it and see if what it tells me.
There was no sign of water on the plugs and the engine is running well and firing on all cylinders even on start up from cold so I don't think water is getting into the combustion chambers at all. But I am losing a small amount of water and there is an oil glaze on the coolant when I drain it and a bit of mayonnaise inside the oil filler cap.
My suspicion is that it is a bad seal on the intake manifold gasket around one of the water passages between inlet manifold and one of the cylinder heads and it is weeping down into the valley from there and down into the sump. I'll pull the intake manifold and leave the heads alone, replace the intake manifold gaskets and see if there is any evidence off losing water.
I'll also check for bubbles in the rad as you suggest Wedgy.
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Apr 2010 Posts: 2,847 Likes: 42 veteran | veteran Joined: Apr 2010 Posts: 2,847 Likes: 42 | Mayo on the oil cap could just be short trip driving in cool weather. O once did an used oil analysis and they indicated Sodium and Potasium, indicating coolant in the oil, and as I suspected the timing chain cover and water pump bolts were allowing coolant past their threads. Some 8 years ago I got a new all Almuinum radiator, 9 months later it was seeping coolant from teh seam where the tubes met the bottom tank. I used some of the Gm coolant fitness tabs, at 1/6th the recommeded dosage and the leak stopped. Same radiator now 9 years later. If i drain teh coolant and refill it without the Ginger root Gm coolant fitness tabs, it wll start weeping at the same exact spots. It never dripped, and was a very slow loss of coolant and if it were a black painted copper brass raditor I might not have noticed where it had been slowly weeping coolant. My heater core is not delivering the same heat it used to though, perhaps that gibgerroot stop leak bars leaks tabs partially plugged it. perhaps the blend door insulation is shot, perhaps both. I plan to backflush it at some point. it stil gets warm, but 22f at 7K feet and 65mph this previous November, it was not effective. So I would say to very closely inspect the radiator where the tubes and fins meet the top and bottom,or side tanks, for signs of weeping. A radiator which does not weep would certainly be better, but I am on year 8 or 9 of the same radiator which weeped at 9 months, thanks to this specific product's efficacy. Lot easier and cheaper than pulling the intake manifold, and if no change, well you will be changing at least a portion of coolant when you do the intake anyway. If GM still sells products in Ireland, Gm relabels this specific prduct and calls them Gm coolant fitness tabs. My landlord is a service advisor at a busy respected auto repair joint, and says most ethelyene glycol coolant using vehicles that have cooling system work done on them go out with a few of these in there to prevent comebacks. | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | There are similar radiator stop leak products here but not those tablets mainly liquid ones likes Wynns or Lucas. Seeing as I've done a lot of other engine dress up work and put new radiator fans on it might be time to treat my van to a new radiator. I can get this one delivered for €130 / €115 seems good value.
https://www.ebay.ie/itm/NEW-RADIATOR-FIT-CHEVY-GMC-G30-G20-G10-SAVANA-G1500-G2500-G3500-1706/192568937868?hash=item2cd600cd8c:g:KJYAAOSw9mpZ5orz
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | Just thinking though, if the leak was in the radiator there would be no reason for the drained coolant to have an oil glaze on it.
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Sep 2005 Posts: 9,855 Likes: 234 carpal tunnel | carpal tunnel Joined: Sep 2005 Posts: 9,855 Likes: 234 | I think you're right about it seeping coolant into the lifter galley. Stock radiators usually have a trans cooler built into them. But any exchange of fluid there would show up pretty quick on the trans dipstick. Have the heads been resurfaced or the block decked by chance? Cutting the block or heads lowers them in relation to the manifold and can cause a mismatch at the intake mating surface. But something like that is usually accompanied by a vacuum leak. Anyway, did the intake bolts line up and screw in okay without a hassle? Do you have any oil seepage at the front or rear of the intake? Maybe the gaskets just slipped a little. It does seem odd that a relatively new set of gaskets would leak coolant but not leak vacuum. LIke you said, just thinking out loud here.
Last edited by CatFish; April 16th 2019 11:39 pm. Reason: kant spel
| | | Re: blown head gasket :eek: | Joined: Apr 2010 Posts: 2,847 Likes: 42 veteran | veteran Joined: Apr 2010 Posts: 2,847 Likes: 42 | The new radiator you linked, the picture appears to show connections for a tranny fluid cooler in one side tank and an engine oil cooler in the other plastic side tank, though the description says it only has the ATF cooler.
Does your existing radiator have an engine oil cooler?
Might be the source of the sheen, if so. If not, could be the tranny cooler leaking into the coolant.
If you have an older copper brass radiator, well lets say the plastic tanked aluminum models are not really built to last. If there are still shops In Ireland than can recore radiators there, they might be a better option. Seems all those shops around here have been killed off by 70$ chinesium radiators.
Regarding the stop leak products. I've read nothing good about any, but the crushed gingerroot tabs I posted a pic of, and these might be responsible for my heater core not transferring heat as it once did. | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | Current radiator only has the trans cooler so it's unlikely to be caused by that as Catfish said. I'll hold off on a new radiator but maybe send it out to be re-cored over the winter when I take the van out of use. Everything is still pointing to the inlet manifold gasket. It don't remember any issue with bolts lining up but it may be just a small failure in the gasket.
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | So finally got round to doing a leak down test and all cylinders came up as good.
Rocker covers are covered in emulsion on the top so it looks as though water is getting past the inlet manifold gasket at one of the water jacket holes , dripping down into the sump and being sprayed up with oil through the push rods to coat the inside tops of the rocker covers. Gonna pull the inlet manifold and investigate that next week.
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Mar 2011 Posts: 513 Likes: 55 addict | addict Joined: Mar 2011 Posts: 513 Likes: 55 | Remember next set gaskets, it's regular maintenance to check the bolts. When new,check after warm up, check at end of day, check in a couple days, check couple weeks, check twice a year. Yup it's a chevy, don't forget the header bolts. | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 |
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | So I've changed the inlet manifold gasket and replaced the radiator. The problem still persists but no issues with any cylinders misfiring or running issues so I still don't think it is getting into the cylinders. Still want to cover other possibilities before taking the heads off. Can water get into the oil without getting into the cylinders due to a bad head gasket? Is there any other water to oil interchange point I should be looking at? There is no oil cooler built into the rad just a tranny cooler, but is there an oil cooler built into the block on an SBC?
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Nov 2013 Posts: 2,286 Likes: 153 veteran | veteran Joined: Nov 2013 Posts: 2,286 Likes: 153 | So I've changed the inlet manifold gasket and replaced the radiator. The problem still persists but no issues with any cylinders misfiring or running issues so I still don't think it is getting into the cylinders. Still want to cover other possibilities before taking the heads off. Can water get into the oil without getting into the cylinders due to a bad head gasket? Is there any other water to oil interchange point I should be looking at? There is no oil cooler built into the rad just a tranny cooler, but is there an oil cooler built into the block on an SBC? Hi Shaggy, 1. Yes. 2. Not positive, but, I don't think so. 3. No. Unfortunately, If there is water mixing with the oil, or oil mixing with the coolant... That motor is so clean, I wouldn't want to have to go that deep either Mate, but. I still enjoy needling Leonard about my "Rebuilt" 327 Plus. William of Ockham came up with that pesky theory called Occam's razor. Cheers! and Good Wrenching! | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | OK thanks for the info Wedgy, Looks like resistance is futile and I'm gonna have to tear it down and fit new head gaskets. If anyone else has any other suggestions for things to check before I get stuck into that let me know.
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Jul 2014 Posts: 4,805 Likes: 123 Uncle Rust N Dents | Uncle Rust N Dents Joined: Jul 2014 Posts: 4,805 Likes: 123 | I wish I had something helpful to add, but I don't.
I'll be doing this myself soon as I just discovered oil in my coolant after the van started steaming off on cold starts. Not the thing I wanted to find, that's for sure.
Hope the job goes easy for you, Shaggy. | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | I'm just putting an order together for rock auto to buy all the necessary parts.
Gaskets for the distributor / inlet manifold / exhaust headers / Cylinder Heads and a new set of cylinder head bolts. I'll get coolant, engine oil flush and fresh oil locally.
Anything I'm missing from that list?
Good luck with yours too Rusty, lets keep posting on this thread and hopefully it'll prove helpful to each other or fellow vanners.
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Jul 2014 Posts: 4,805 Likes: 123 Uncle Rust N Dents | Uncle Rust N Dents Joined: Jul 2014 Posts: 4,805 Likes: 123 | That's a good idea. I'll try to add if I can. I'm not quite sure yet how, if, and when I'm going to do mine. I'm still a little stunned at the bad timing (I've already got too many stalled projects). | | | Re: blown head gasket :eek: | Joined: Jun 2010 Posts: 18,286 Likes: 559 | Joined: Jun 2010 Posts: 18,286 Likes: 559 | Sell the rest ... fix the best !
SUNSHINE VANS-VAN DIEGO ADRENALIN BY THE GALLON & CHASIN RACIN ONE FOR THE DIRT & ONE FOR THE STREETS '93 CHEVY G30 454 4X4 SPORTVAN EXT 146" WB '92 CHEVY G30 454 BEAUVILLE EXT 146" WB | | | Re: blown head gasket :eek: | Joined: Nov 2013 Posts: 2,286 Likes: 153 veteran | veteran Joined: Nov 2013 Posts: 2,286 Likes: 153 | I'm just putting an order together for rock auto to buy all the necessary parts.
Gaskets for the distributor / inlet manifold / exhaust headers / Cylinder Heads and a new set of cylinder head bolts. I'll get coolant, engine oil flush and fresh oil locally.
Anything I'm missing from that list?
Valve cover gaskets. Plus have a quality machine shop that you trust check the heads if there is any question on condition. Save you a ton of heartache, time, and money. Good Wrenching! | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | Yep got valve cover gaskets too (3 sets for some reason). Cheers Wedgy.
79 chevy G30 cobra camper conversion. | | | Re: blown head gasket :eek: | Joined: Mar 2011 Posts: 513 Likes: 55 addict | addict Joined: Mar 2011 Posts: 513 Likes: 55 | Are you luck ducky, got a 400? You may have thought of this, watch the breakaway torque of the bolts. It may give you a clue. Other thoughts any bolt hole that protrudes into the coolant will need thread sealant, it seals the bolt and lubricates the thread to achieve proper torque. The strait six in the brown van died for the same problem. | | | Re: blown head gasket :eek: | Joined: Apr 2004 Posts: 2,027 Likes: 51 veteran | OP veteran Joined: Apr 2004 Posts: 2,027 Likes: 51 | No not a 400 but a 350 bored 60 thou over (so nearly). I've ordered fresh bolts and will seal them with Loctite medium threadlock. Thanks jcd74.
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