Blown Civic
 

Hey all! Been lurking for a while, decided to post.

My DD is a '96 Taurus w/ 3L V6, ~24mpg :eek:. Daily commute is ~35 miles, through mountains. I've improved my mpg 10-12% just by driving behavior modification tips I learned about here :thumbup:. Mostly easy starts and stops, and motion conservation, neutral gliding and gentle hill climbing.

I'm wanting to go to something better on gas, and I have a project. It used to be my daily driver. It's an '02 Civic LX sedan with a blown engine (broken rod, hole in side of block), that, funny enough, still runs on the 3 remaining cylinders.
It got pretty good MPG with it, I once got 42 on a road trip.

My question is, what do I replace the D17 with? I've read about swapping in a D15 VX engine in older (92-95?) Civics, but didn't know if there was an option for my 7G Civic. I plan on pulling the engine this summer/fall and either replacing/repairing the block or swapping in a whole used (JDM, prob) engine.

I realize the sedan is heavy-ish and might not like a smaller engine. Of course, there's the custom motor mounts and other junk needed. Should I just drop in a direct replacement, or is there another option? :confused:

Thanks!

Welcome!

There are several of us on here that have 7th Gen Civics. Mine is an 05 Sedan with a 5 speed.

As far as I know, the only engine that will bolt to a 7th gen transmission is a D17. I don't think a D15 will bolt to your transmission. But, you could always swap out the transmission too. Is this an auto or manual? If you have a manual and swap in older generation's manual, you will be going from a cable shifted to the rod shifted.

Then there is the ECU to reprogram and replace. A swap might end up costing more than the MPG increase is worth. I'd throw in a junkyard/Craigslist D17 (new timing belt, water pump, etc) and call it a day. If you have a manual transmission, you should be able to hit 40 MPG at a minimum. Up until it got blazing hot here and I started using the AC, I was able to keep a 40 MPG average in traffic.

But, if you wanted to do something different, grab an EX/HX motor and HX ECU (can 7th Gen Civic's ECU even be swapped? I am thinking out loud...) and throw it in your car. Then, you can have a lean burn sedan!

Okay, I just went to your garage. You have a manual transmission.

Hello and welcome to the site.

I'm fixing up an 02' Civic LX too. :)

I'd just replace the blown engine as well. The Civic can get very respectable mileage without something non-stock.

Thanks Daox! GL on yer fix-up. My car had been pretty good to me, until the engine blew in the mountains in winter. That sucked. Oil everywhere, nice hole in the block.

OK, just found a craigslist D17 for $600 OBO. Though it's a VTEC and mine's not. I don't remember what it takes to make that work.

Your D17 will bolt-on a D15 transmission, but there will be some shifter linkage fabrication (you have cable whereas 5th and 6th gen had rods). I don't know if the older engines will swap in, and there is a security immobilizer to consider in the 01-05 Civic.

Other thoughts... you could get the whole D17 Civic HX engine and bolt it in, needing the wiring harness, ECU, and HX transmission. That would give you a learn burn "HX/LX" or "HLX." Increase the complexity of that idea further and get a 1992-1995 CX/VX trans.

More simply, bolt in a new D17 LX engine, keep your current harness, ECU, and then decide if you want to keep your transmission or buy an 2001-2005 HX transmission for its taller gearing. A 2001-2005 HX trans will bolt right onto your "new" 2001-2005 LX engine.

BTW, I compiled as rigorously as possible a variety of transmission specs for these cars: http://ecomodder.com/forum/showthrea...tml#post378478

Welcome to "the fold."

james

The VTEC has a different cam and head. It also has a VTEC solenoid. I am not sure if you can run a VTEC engine without a VTEC computer. If you get the computer, the wiring harness is different. I think it's only the VTEC wire. I was looking into what it would take to swap mine over to an HX.

Did you check Car-Part.com--Used Auto Parts Market for a non-VTEC engine?

Have you bolted a D15 trans to a D17 motor or vice-versa? Everything I have found says they won't bolt up, though I've never tried it. Now I'm curious.

Good question, I should have said so... I have not done this swap. I swapped a fith gen CX trans onto my 6th gen DX engine. But one of the comments on my transmission specs thread, by Darcane, offered some evidence of the limits and possibilities. He supplied this link as evidence: 2005 EM2 old school d series swap - D-series.org

If it will bolt one way, it will bolt the other way. It's just a matter of some fabrication.

The OP on this thread wants a D15 on the D17 tranny, just like the link above. They should physically bolt together...

Lots of other fabrication may need to happen though (engine mounts, sorting out the wiring, etc).

Also, there were flavors of D15 installed in these cars for the European market.

Yeah, I thought it was something like that. Been a while since I researched it. HX does sound better.

Cheapest price on car-part.com is $250 from Brooklyn. Shipping is prob $150-200.
eBay is $450-800.
Locally my salvage yards don't have any.
craigslist has a VTEC for $600.

[THINKING OUT LOUD] Is it possible to properly repair a damaged block? Either casting new material and welding onto the hole, or repairing the hole in some other way? I'll have to replace the broken rod and maybe piston, and check and make sure there's not other internal damage, but if the hole is fixed, shouldn't the engine be OK? Or are there stresses that will flex and break the block even if repaired?[/THINKING OUT LOUD]

Just trying to avoid spending extra $$$ if I don't have to.:p

Note that there are two VTEC engines. The D17A2 VTEC found in the EX, and the D17A6 VTEC-E found in the HX. The HX is capable of lean burn which is nice for economy.

Gear ratios are best for efficiency in the HX tranny, worst in the EX tranny. Finding an HX tranny might be a good idea. Regardless which tranny, be aware that the Input Shaft Bearing is a common point of failure and you may want to replace it while you have it apart.

You probably could repair the block, but it would be way more time and money intensive than just swapping in a different engine. That, and it probably wouldn't hold up as well.

Thanks for the welcome, and for that link.

Cool as I think a VX engine in the LX (LVX? VLX?) would be, I think at this point a direct replacement D17 is in order. I could, but don't want to fab custom mounts/linkages/wiring.

What's the (assumed average) mpg savings for the HX tranny? The gearing looks different enough to make a real impact on mpg. I'm interested in exploring this option, seeing as I'll have the engine out anyway.

All that aside, however, I did find some VX engines for $200-300. And if it will bolt up to a LX or HX tranny...that would be sweet. :D

Yes, but is it possible to use the EX engine as an HX engine with the HX ECU? I think the pistons and cams are different, but otherwise the motor is the same.