tuko Posted June 15 Share Posted June 15 The last few weeks the 300tdi developed a strange periodic overheating issue which came out of now where's. Remember that this is a used engine from a Disco with 20T km, but all the accessories are replaced with brand name items. Anyways the temp gauge will spike to red and stay there for a few minutes and drop just as fast. A number of times when it was showing red on the gauge I would open the bonnet and there is excessive pressure blowing off from the expansion tank but no liquid. So with my experience with LR and talking with 2 mechanics, one being a LR dealer mechanic we came to the conclusion that it's one of 3 possible things. 1) ground issue with the gauge/s ? 2) thermostat is no working properly 3) water pump is not working properly. So after going through the instrument cluster and yes finding a bad ground I thought that I got it, but nope! Yesterday I replaced the thermostat with a LR original unit and removed the water pump. Now the water pump I didn't bother replacing it for 2 reasons, 1) it was perfectly fine, no issues to found any where's and 2) the quality of it (Dayco unit) was far superior that the new SKF pump I had in stock. The propellers were so much beefier in the Dayco pump that I simply thought no way I was changing it to a water pump that has smaller and not as well put together. With a new thermostat and new coolant (50/50) blend I test drove the Defender again last night and when the engine was under load for example at highway speeds the temp gauge spiked again, but would drop when I got back to city driving and taking it easier on the gas pedal. I will add that I have noticed but not really thought too much about till now is that the engine seems to need a bit more throttle pressure to get the same speeds. I've not noticed any white smoke from the exhaust nor is there any contamination in the engine oil. I've been googling this morning and one thing that has come to the forefront and that I never thought about till now is that the head is cracked. I've never had a cracked 300Tdi head before, so this is a new one for me. With the symptoms that I have described, with the wealth of knowledge here, am I on the right path thinking that the head is the issue? Your opinions are appreciated, Todd. Quote Link to comment Share on other sites More sharing options...
miketomcat Posted June 15 Share Posted June 15 It could just be a head gasket. Obviously if you do that you can check the head too. Mine didn't overheat when the head cracked but it was noticeable however mine is a 200 so less prone to overheating anyway. Mike Quote Link to comment Share on other sites More sharing options...
tuko Posted June 15 Author Share Posted June 15 2 minutes ago, miketomcat said: It could just be a head gasket. Obviously if you do that you can check the head too. Mine didn't overheat when the head cracked but it was noticeable however mine is a 200 so less prone to overheating anyway. Mike Mike, thanks for your quick reply. Yes it could be a head gasket but have you ever seen an Erling head gasket go bad after only 2 years of usage? Is there any tell tail signs that I can look for? Todd. Quote Link to comment Share on other sites More sharing options...
elbekko Posted June 15 Share Posted June 15 Sounds like head gasket or cracked head, yes. Do you also lose heating when the gauge spikes? Quote Link to comment Share on other sites More sharing options...
tuko Posted June 15 Author Share Posted June 15 1 hour ago, elbekko said: Sounds like head gasket or cracked head, yes. Do you also lose heating when the gauge spikes? I don't know, never really thought about that to be honest. Quote Link to comment Share on other sites More sharing options...
tuko Posted June 15 Author Share Posted June 15 The plot thickens, about an hour ago I went out to the Defender and removed the thermostat housing nut, the radiator nut and the expansion tank cap, all 3 locations show the antifreeze levels low. So starting at the expansion tank I filled it up till the thermostat housing was full and closed the nut again. Then I topped up the radiator till it was full and closed that nut. Finally the expansion tank topped up to the middle. Joking with the wife I said I'm going to change the expansion tank cap from my other LR, because the one on the Defender was releasing pressure even when the antifreeze felt cool. I've been out and drove over 30km, all types of driving from city to highway with passing other vehicles, the temp gauge was steady as a rock at center on the gauge. Once home I opened the bonnet and not a whisper of any sounds from the expansion tank and no leaks. If what appears to be a defective expansion tank cap, could that be causing the issues that I have been experiencing and possibly wrongly diagnosed? I've never experienced this before and if it's simply a replacement cap, I can live with that, it's certainly cheaper than tearing down the engine. Todd. 1 Quote Link to comment Share on other sites More sharing options...
elbekko Posted June 15 Share Posted June 15 Fingers crossed it's just that, definitely possible. 300TDis love getting air pockets when they loose a bit of coolant, and then you get the gauge spikes. 1 Quote Link to comment Share on other sites More sharing options...
fmmv Posted June 15 Share Posted June 15 Agreed, possibly just attention seeking. We had one do it, and for about 2 months it kept overheating then it's gone years OK. There was no obvious air pocket and the heater worked. Impossible to diagnose when it has disappeared. Quote Link to comment Share on other sites More sharing options...
tuko Posted June 15 Author Share Posted June 15 Guys unfortunately the excitement was short lived. We drove an additional 70 km this afternoon, when I parked the Defender at the trail head, the expansion tank was percolating like the coffee maker in the morning and pissing out antifreeze everywhere. What gets me is that the entire drive I had my eyes glued to the temp gauge and it was rock steady in the middle, even in the parking lot when we stopped. Clearly the new thermostat is working and keeping the temps at bay BUT it is building pressure somewhere and it's blowing off at the expansion tank. After the 1½ hour hike, I checked the expansion tank thinking that I would have to fill it but it was now over the middle line and didn't require any topping up for the trip home. When home of course the expansion tank was at it again and the temp gauge was fast in the middle. I think I'm back at square one. I'm going to pull the head tomorrow and will have to see if I can get it pressure tested and skimmed, if it's warped or cracked? Todd. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted June 15 Share Posted June 15 Are you sure you didn't just overfill it? The excess will come out if there is no room for expansion. Quote Link to comment Share on other sites More sharing options...
miketomcat Posted June 15 Share Posted June 15 10 hours ago, tuko said: Mike, thanks for your quick reply. Yes it could be a head gasket but have you ever seen an Erling head gasket go bad after only 2 years of usage? Is there any tell tail signs that I can look for? Todd. Simple answer is yes, I've had several go in under 2 years. I'm not known for hanging about and I've heard there may be some dodgy erling head gaskets. I've also had some that look undamaged when removed but changing it has fixed the problem. It does sound like an air lock but that could be caused by a blown head gasket. Mike Quote Link to comment Share on other sites More sharing options...
Paul C Posted June 16 Share Posted June 16 Mine was overheating and getting airlocks when the head gasket leaked between cylinders 2 and 3. Had to skim 12thou off the head to straighten it. It hasn't overheated since. I have a new head in the shed now but won't fit it until I fit the 2.8 kit. Quote Link to comment Share on other sites More sharing options...
tuko Posted June 16 Author Share Posted June 16 Well the head is off. Mike, you were on the money! The obvious sign of blowby is from cylinder 3 and the water passage between cylinders 3 and 4. Do you guys see anything else I should be concerned about? I did place a straight edge on the deck then ran a light behind it, yes the head needs skinning with the rear showing the most light. I will get the head pressure tested at the same time of skimming so that we are sure it's good to go or an anchor. Todd 2 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted June 16 Share Posted June 16 Get it skimmed and slap it back on 1 Quote Link to comment Share on other sites More sharing options...
tuko Posted June 17 Author Share Posted June 17 21 hours ago, Bowie69 said: Get it skimmed and slap it back on I left at the machine shop after work this evening, the guys said it will be ready in 2 days. Head gasket should be here by Thursday, so I might have it back together by the long weekend. Fingers crossed. Todd 2 Quote Link to comment Share on other sites More sharing options...
Popular Post tuko Posted June 18 Author Popular Post Share Posted June 18 The head was gone for just 24 hours and it's already back in my garage. 3/10th mm was removed, the machinist said it was just the second head he has even see that was twisted in the center. He wants me to pay closer attention to the block bores for the head bolts. Advice I'll listen to. 😉 Todd. 5 Quote Link to comment Share on other sites More sharing options...
Maverik Posted June 19 Share Posted June 19 When I rebuilt my 200tdi from a Turner short block about 4 years ago, I went through 2 erling headgaskets within 6 months, it was super frustrating as I couldn't understand why, I was pretty fastidious in how I installed them too, last time I did it I was almost surgical in my fixing, and it seems to have been ok. I very nearly went back to a steel shim type headgasket as I suspected the erling composite ones I was being supplied weren't up to the task. 1 Quote Link to comment Share on other sites More sharing options...
tuko Posted June 19 Author Share Posted June 19 The excitement of getting the new head gasket was short lived! How the f'n can a person pack a head gasket in bubble wrap? Then think that Schenker is not going to throw it around like it's not theirs and then the customer is going to be pleased with the whole affair? Well, so much for getting the Defender back on the road this weekend. 😞 BTW, I did try straightening it out but the steel around the #3 cylinder hole began to open from the gasket material. There are no kinks in the gasket material, just the metal opened up slightly. Of course it would be pressed back together with the head but is it worth the risk of having to do this job all over again? Todd. 3 Quote Link to comment Share on other sites More sharing options...
elbekko Posted June 19 Share Posted June 19 Yeah, I wouldn't trust that either. Unbelievable! Quote Link to comment Share on other sites More sharing options...
miketomcat Posted June 19 Share Posted June 19 I bought a head gasket recently and was very impressed to find it taped to a piece of 6mm ply, wrapped in bubble wrap, in a box. Mike 2 Quote Link to comment Share on other sites More sharing options...
Maverik Posted June 20 Share Posted June 20 Yup - had the same problem before and that was from Turners too who you'd have thought would have know that you might want the HD gasket nice and flat... bin it get another one. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted June 20 Share Posted June 20 It's times like these I use a local motor factor, they can get things often faster than mail order and know how to treat parts. 3 Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted Thursday at 07:33 AM Share Posted Thursday at 07:33 AM 57 minutes ago, Bowie69 said: It's times like these I use a local motor factor, they can get things often faster than mail order and know how to treat parts. My local also set up a cash account for me so that I don't have to keep track of when I ordered parts etc., they'll have it all on their system. I wouldn't use them for actual work on the vehicles since years ago they managed to take out a turbo doing an oil change. Case in point day before last at 1630 I noticed that the crank damper pulley was knackered. Phoned them up - they didn't have one in stock but got one on order. 10am the next morning phone call saying it had arrived, went down and picked it up in the afternoon, along with a Dayco timing kit and both Corteco front crank seals. Few hours later it was back up and running. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted Thursday at 07:47 AM Share Posted Thursday at 07:47 AM Agreed, similar experience tbh. And dare I say it, Euro Car Parts are getting better at this, order one day, there the next or even that afternoon and you can do it online. Returns are easy too, unlike when doing things by post. Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted Thursday at 08:13 AM Share Posted Thursday at 08:13 AM @tuko having had a few "overheating" issues on a 300Tdi I can list symptoms and causes fairly well. Electrical issues - I've still got my original temperature gauge and to be honest components of that era seem to be better built than modern stuff. The dash earths onto the bulkhead (stud in engine bay) but the bulkhead earth's through the chassis and takes its primary path via a P clip near the battery box. The insulation on the negative lead is stripped back and the P clip grounds it. I had the gauge over reading and would steadily rise - rather ironically with bumps on the road and you could also see the dash lights flicker once in a while. To test this if you think it may be an issue by once it's over reading turn off the ignition, let the gauge settle back and then turn it back on. Chances are the gauge will settle at a lower temperature. If it were genuinely hot then it should return pretty quickly to hot. Radiator issues - I overheated once towing a big load on the M4, that turned out to be the bottom of the rad being partially blocked with a combination of sludge internally and detritus externally in the fins. It was fine most of time but towing a very unaerodynamic load highlighted it. I also had one recently where I saw drops from the front once in a while but nothing consistent but over time the level would drop. I needed to swap hoses and give it an oil change so took the opportunity to flush the rad with a hose. After reinstalling everything was fine until I revved it up by hand on the IP and got a face full of coolant. There was a pinprick hole down low in the rad which was being intermittently blocked and unblocked by the small amount of sludge in the system. Hoses - I noticed some dampness around the top rad hose on the thermostat, after 30 years they were finally beginning to crack, or so I thought. I've installed new ones but I think it was actually a jubilee clip giving up. This was difficult to spot over the winter because it's been so wet but fairly obvious once things dried out. In this time I don't think I've ever had a head gasket cause coolant issues (blowing out of #4 yes). There was one time where it was getting warm seemingly randomly and as I had a spare head I swapped it over and issues disappeared for a while but that was before I discovered the dodgy earth via P clip on mine. 2 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.